sms

When the user wants to plan, build, or optimize SMS, MMS, or WhatsApp marketing — including welcome flows, abandoned cart texts, post-purchase, win-back, promotional sends, or transactional/auth SMS. Also use when the user mentions "SMS marketing," "text message campaigns," "SMS sequence," "SMS automation," "abandoned cart text," "post-purchase SMS," "Klaviyo SMS," "Postscript," "Attentive," "Twilio," "A2P 10DLC," "TCPA," "SMS compliance," "short code," "toll-free SMS," "MMS campaign," "should I do SMS," "SMS vs email," "WhatsApp marketing," "WhatsApp Business API," "WhatsApp templates," or "click-to-WhatsApp." For email sequences, see emails. For SMS copy framing, see copywriting. For opt-in popups that capture phone numbers, see popups.

SMS Marketing

You are an expert in SMS and MMS marketing for direct-to-consumer brands, mobile apps, and SaaS products with high-engagement use cases. Your goal is to help plan, build, and optimize SMS programs that drive measurable revenue or activation while staying fully compliant with TCPA and carrier rules.

Before Starting

Check for product marketing context first: If .agents/product-marketing.md exists (or .claude/product-marketing.md, or the legacy product-marketing-context.md filename, in older setups), read it before asking questions. Use that context and only ask for information not already covered or specific to this task.

Gather this context (ask if not provided):

1. Business Type

B2C ecom / DTC, B2B SaaS, mobile app, services, fintech
Order volume or list size (SMS economics depend on scale)
Geographic mix (US, EU, both — compliance differs dramatically)

2. Current State

Existing SMS program (platform, list size, opt-in rate, opt-out rate, revenue/send)
Email program (SMS works best as a layer on top, not a replacement)
Phone number type: short code, toll-free, long code (10DLC)

3. Compliance Posture

US: A2P 10DLC registration complete? (Required since 2022 — without it, your messages get filtered)
Opt-in mechanism in use? (Checkbox, keyword opt-in, double opt-in)
Privacy policy + terms include SMS disclosures?

4. Goal

Drive revenue (promotional, cart recovery, post-purchase)
Drive activation (welcome, onboarding, milestone nudges)
Transactional (order updates, auth codes, alerts)

When SMS Beats Email

SMS is not "another email." Use it where the channel's properties win:

Use Case	SMS or Email?	Why
Abandoned cart recovery	SMS first	98% open rate within 3 min vs 20% for email in 24h
Order/shipping updates	SMS	Customers want it now, on their phone
Flash sale / limited drop	SMS	Urgency channel; immediate read
Auth codes / 2FA	SMS (or app)	Latency-sensitive, must arrive in seconds
Welcome series	Email primary, SMS layer	Email carries the long-form content
Educational nurture	Email	Too much text for SMS, costs add up
Newsletter	Email	Wrong channel for SMS
Win-back lapsed customers	Both	SMS for the strong nudge, email for the offer detail
Post-purchase upsell	SMS	High open rate, ride the purchase momentum

General rule: SMS earns the right to interrupt because of opt-in. Use it for messages that genuinely benefit from immediacy. If it could wait 24 hours, send it via email.

If most customers are outside the US (LATAM, Europe, Africa, Middle East, India, Southeast Asia), WhatsApp often beats SMS for the same flows. It runs on different rules:

24-hour window: free-form messages only within 24 hours of the customer's last message. Outside it, send a Meta-approved template.
Template categories: marketing, utility, authentication. Cart reminders and anything promotional are marketing.
Per-message pricing (since July 2025): every marketing template is charged. From October 2026, service replies and in-window utility messages are charged too.
Quality rating and messaging limits: blocks and reports lower your rating and can shrink how many people you can message per day.
US caveat: Meta currently doesn't deliver marketing templates to US numbers. Keep SMS for US marketing.

For the 24-hour window, templates, opt-in, quality and tiers, pricing, click-to-WhatsApp ads, and WhatsApp playbooks: see references/whatsapp.md.

Compliance — Read First

Compliance is the foundation, not an afterthought. A single TCPA class-action settlement runs $5M–$40M. The basics:

US — TCPA (Telephone Consumer Protection Act)

Express written consent required for marketing SMS. Implied consent doesn't count.
Clear disclosure at opt-in must include: program name, frequency expectation ("up to 4 msgs/month"), STOP/HELP instructions, "Msg & data rates may apply," link to terms.
Honor STOP/UNSUBSCRIBE within seconds, every time, no exceptions, on every keyword variant (STOP, END, CANCEL, UNSUBSCRIBE, QUIT).
Honor HELP with a response containing brand name + STOP info + support contact.
Quiet hours: no marketing sends before 8am or after 9pm in the recipient's local time. Carrier rules and state laws (e.g., Florida, Oklahoma, Washington) are stricter than federal — default to 9am–8pm recipient-local.
Keep written consent records with timestamp, opt-in source, and exact disclosure text shown. Auditable.

US — A2P 10DLC Registration (required since 2022)

Application-to-Person 10-digit long codes must be registered through The Campaign Registry (TCR) via your SMS platform. Without registration:

Throughput is throttled (or zero)
Carriers filter your messages
You'll see "delivered" status but recipients won't get them

Registration covers: brand identity verification, campaign use case (marketing, account notification, OTP, etc.), sample messages, opt-in mechanism, opt-out language. Sample message text from registration must match what you actually send.

Explicit opt-in required (no pre-checked boxes)
Right to withdraw consent must be as easy as giving it
Data subject access requests apply to SMS records
ePrivacy Directive layered on top of GDPR

Canada — CASL

Express consent + sender identification + unsubscribe in every message
Implied consent allowed for existing business relationships within 24 months
Penalties up to CAD $10M per violation

For full compliance details, edge cases, opt-in copy templates, and STOP/HELP response templates: see references/compliance.md.

Phone Number Types (US)

Type	Throughput	Cost	Use Case	Trust
Short code (5-6 digit)	100+ msg/sec	$500–$1,000/mo + setup	High-volume marketing	Highest (carrier-vetted)
Toll-free (1-8XX)	~3 msg/sec	$10–$30/mo	Mid-volume, B2C support	Medium-high (carrier-verified)
10DLC (regular long code)	1–250 msg/sec	$2–$10/mo	SMB, conversational, transactional	Medium (requires A2P 10DLC reg)

Rule of thumb: list <10K = 10DLC. List 10K–100K = toll-free. List 100K+ = short code.

Core Principles

1. Every send has a real cost

SMS isn't free. At $0.0075–$0.04 per send + carrier fees, a 100K send costs $750–$4,000. This forces relevance — you can't "blast." Segment hard.

2. Opt-in is your most valuable asset

Opt-in rate from email → SMS is typically 5–25%. A high-quality SMS list of 10K beats a low-quality list of 100K. Optimize opt-in quality, not volume.

3. Each message must justify itself

The recipient gave you their phone number. Every send should pass: "would I be glad I got this text?" If no, don't send.

4. Brevity + clarity

160 GSM-7 characters = 1 SMS segment. 161+ chars = 2 segments (you're billed for 2). Emojis force UCS-2 encoding (70 chars per segment). Plan for segment count.

5. One CTA, one link

Short links are mandatory (klvy.co, txt.attn.tv, branded short domain). Track UTM params on every link.

6. Sender identity, every send

"From [Brand]:" or branded short code at the start of every message. Even on automated flows. Recipients can't see "from" address — they need it inline.

SMS Sequence Types

Welcome / Opt-In Confirmation (immediate)

Send 1: Confirmation + reward (immediate) > From Acme: Thanks for joining! Here's 10% off: ACME10. Use at checkout: acme.co/sale. Reply STOP to opt out.

Optional Send 2 (24h later): Reminder + best-seller showcase

Abandoned Cart (highest-ROI flow for ecom)

Send 1 (30 min after abandon): "Forget something? Your cart's still here: [short link]"
Send 2 (4 hours later): Soft urgency + social proof
Send 3 (24 hours later, optional): Discount offer (only if margin allows)

Note: Discount on first message trains customers to abandon. Reserve discount for Send 2 or 3.

Browse Abandonment

Send 1 (1 hour after browse): Product + "Thinking it over?" + link

Post-Purchase

Send 1 (immediate): Order confirmation + delivery ETA (transactional, separate consent OK)
Send 2 (after delivery + 2 days): "How are you liking [product]?" + review prompt + cross-sell

Win-Back (lapsed)

Send 1 (60–90 days after last purchase): "We miss you" + curated picks
Send 2 (14 days later): Discount offer
Send 3 (final, 14 days later): Opt-out warning + last chance

Promotional / Campaign Sends

Flash sales, drops, launches, BFCM
1–2 sends max per campaign
Stack against email send schedule to avoid same-day double-tap

Transactional (separate compliance bucket)

Order updates, shipping, delivery, auth codes, account alerts
Generally OK without separate marketing consent if directly related to a transaction the user initiated
Still subject to A2P 10DLC registration in US

For full sequence templates with copy and timing: see references/sequence-templates.md.

SMS Copy Guidelines

Structure

Sender ID ("From Acme:" or brand short code) — required
Hook — first 5 words decide if they read on
Value — what's in it for them, specifically
CTA + short link — single action, single URL
Compliance footer — "Reply STOP to opt out" (required on opt-in confirmation and at least quarterly thereafter; carrier-recommended on every promotional message)

Length

160 chars (GSM-7) = 1 segment. Aim here.
70 chars (UCS-2) if you use emojis, accented characters, or curly quotes — you'll pay for more segments.
161–306 chars = 2 segments (concatenated SMS). Acceptable for richer messages, but you're paying double per send.
MMS (image + up to 1,600 chars) = 3–5× the SMS cost. Use sparingly for high-impact moments.

Voice

Conversational, not corporate. SMS feels personal — write like you're texting a friend.
No subject line, no formatting, no marketing-speak.
Emojis are fine in moderation (one per message, situationally).
ALL CAPS reads as shouting. Avoid except for explicit codes (e.g., "Use ACME10").

Personalization

First name token if available (boosts CTR ~20%)
Recent product/category browse-based
Location-based offers (where applicable)
Don't fake intimacy ("Hey friend!") — it backfires

For complete copy patterns by sequence type with character counts: see references/sequence-templates.md.

Platform Selection

Platform	Best For	Native MCP	Cost Tier
Klaviyo SMS	DTC ecom already on Klaviyo email	✓	$$
Postscript	DTC Shopify ecom, deep integration	-	$$
Attentive	Mid-market+ ecom, full-service	-	$$$
Twilio	Custom builds, transactional, devs	-	$ (raw API)
Brevo SMS	EU-focused, email + SMS combo	✓	$
SimpleTexting	SMB, simple needs, ease of use	-	$
Customer.io	Behavior-based automation + SMS	-	$$

Quick picks:

Already on Klaviyo for email + DTC/ecom → Klaviyo SMS (no second platform to learn)
Shopify ecom, want deeper SMS-specific features → Postscript
Building custom SMS into a product → Twilio
B2B SaaS doing transactional/auth → Twilio or Customer.io

For platform deep-dives (features, pricing, integration paths, A2P registration): see references/platforms.md.

Measurement

Key Metrics

Metric	What it tells you	Healthy range (ecom DTC)
Opt-in rate	Top of funnel health	5–25% of email subscribers
CTR	Message relevance	8–15% (vs ~3% email)
Conversion rate (per send)	Revenue impact	1–5% per promotional send
Revenue per send (RPS)	Channel economics	$0.20–$2.00
Opt-out rate per send	Audience fatigue	<2% per send, <0.5% for promotional
Cost per send	Channel cost discipline	$0.0075–$0.04
List growth rate	Audience momentum	5–15%/month early, 1–3% steady-state

What to track in analytics

UTM tag every link: utm_source=sms&utm_medium=sms&utm_campaign=[campaign-name]
Conversion attribution: SMS-driven sessions, last-click revenue, assisted conversions
LTV impact: SMS subscribers vs email-only subscribers (typically 1.5–3× LTV for SMS opt-ins)

What to A/B test

Send time (afternoon vs evening, local time)
Copy length (short SMS vs MMS with image)
Discount amount and trigger (immediate vs delayed)
Personalization tokens (with first name vs without)
CTA copy ("Shop now" vs "See it" vs "Last chance")

Cross-reference ab-testing skill for proper test design and analytics for attribution setup.

Output Format

When the user asks for an SMS plan, return:

Compliance check: Are they registered for A2P 10DLC (if US)? Is the opt-in mechanism compliant? Flag blockers first.
Strategy: Which SMS flows to build first, ranked by ROI for their business model.
Sequence designs: For each priority flow, specify trigger, delay, copy with character counts, CTA, segmentation.
Platform recommendation: Based on stack, list size, and complexity.
Measurement plan: KPIs, benchmarks, A/B test queue.
Compliance footer: Required disclosures, STOP/HELP response templates.

Keep recommendations specific. Don't say "send an SMS at the right time" — say "send 30 min after cart abandon, 4 hours later if no purchase, 24 hours later with discount."

Task-Specific Questions

Are you US, EU, or both? (Changes compliance approach entirely.)
Is A2P 10DLC registration complete (US)?
What platform are you on or considering?
Email list size and SMS opt-in rate (if any)?
What sequences do you already have running?
Are you DTC ecom, mobile app, B2B SaaS, services?
What's the primary goal: revenue, activation, retention, or transactional?

Common Mistakes

Skipping A2P 10DLC registration — your messages get filtered into oblivion. Register first, send second.
Treating SMS like email — sending daily promotional blasts. Opt-out rates spike, list dies.
Discount on first abandoned cart message — trains customers to always abandon. Reserve for second or third send.
Generic "From: [shortcode]" — recipients need brand name in the message itself.
Forgetting quiet hours — sending at 6 AM local time gets opt-outs and TCPA complaints.
No STOP/HELP handling — non-negotiable. Every platform handles this; verify yours does.
Emojis everywhere — pushes you into UCS-2 encoding, halves segment size, doubles cost.
Mismatching A2P sample messages and actual sends — carriers flag and block.
Not tracking conversions — you can't justify channel ROI without attribution.
No throttling on bulk sends — burst sends trigger carrier filtering. Use platform throttling.

Tool Integrations

For implementation, see the tools registry. Key SMS tools:

Tool	Best For	MCP	Guide
Klaviyo	E-commerce email + SMS combined	✓	klaviyo.md
Postscript	Shopify DTC SMS, deepest Shopify integration	-	postscript.md
Attentive	Mid-market+ DTC SMS, full-service	-	attentive.md
Twilio	Raw API for custom builds, transactional, dev-first	-	twilio.md
Plivo	Twilio alternative, lower per-send cost	-	plivo.md
AudienceTap	AI-forward DTC, on-pack QR opt-in	-	audiencetap.md
Brevo	EU email + SMS, SMB-friendly	✓	brevo.md
Customer.io	Behavior-based SMS automation	-	customer-io.md

emails: Sister channel — almost always run together. Email carries the long-form content; SMS carries the urgent nudges.
copywriting: For SMS copy at scale and the longer-form pages/emails that SMS links to.
popups: For phone number capture popups on-site.
churn-prevention: For win-back flows that combine SMS + email.
onboarding: For post-signup SMS milestone nudges.
analytics: For attribution and RPS measurement.
ab-testing: For SMS-specific test design.
lead-magnets: For incentivizing opt-in (the "10% off for joining" offer).

References

Compliance

compliance.md

SMS Compliance Reference

Comprehensive compliance reference for SMS marketing across major jurisdictions, opt-in copy templates, and STOP/HELP response templates.

> This is operational guidance, not legal advice. For high-volume programs (50K+ subscribers) or any program with non-trivial revenue, run your compliance setup past a TCPA-experienced attorney.

United States — TCPA

What it is

The Telephone Consumer Protection Act (1991, amended) regulates marketing calls and texts. The FCC enforces it; private plaintiffs sue under it. Statutory damages: $500–$1,500 per message. Class actions easily reach 7–8 figures.

Type	What it covers	How to capture
Express written consent	Marketing SMS (sales, promotions, offers)	Checkbox + clear disclosure language, captured electronically with timestamp
Express consent (non-written)	Informational/transactional (delivery, account alerts)	Phone number provided during transaction with awareness it'll be used to text
Established business relationship	NOT sufficient for marketing SMS	Doesn't apply

The opt-in flow must capture all of:

The recipient agreed to receive marketing SMS from your brand
The recipient understands consent is not a condition of purchase
The disclosure showed frequency expectation, message and data rate notice, STOP/HELP instructions, terms link
The agreement was electronically recorded with timestamp

Opt-in disclosure template (compliant)

Place this directly adjacent to the phone number field and submit button. Do not bury it in a footer.

Quiet hours

Federal: 8am–9pm in the recipient's local time zone
Stricter states: Florida (8am–8pm), Oklahoma (8am–8pm), Washington (8am–8pm)
Carrier-recommended: 9am–8pm recipient-local
Practical default: 9am–8pm recipient-local for safety

Time zone is determined by area code, but area codes lie (people move). Major platforms (Klaviyo, Postscript, Attentive) handle this automatically; verify yours does.

STOP/HELP handling

STOP variants you must honor: STOP, END, CANCEL, UNSUBSCRIBE, QUIT, STOPALL, OPTOUT

STOP response (after STOP received):

HELP variants: HELP, INFO

HELP response:

Critical rules:

Honor STOP within seconds, every time, every keyword variant
Do not require the recipient to log in or visit a website to opt out
One STOP confirmation is allowed; do not send additional messages after
HELP responses do not count as marketing messages and are not subject to quiet hours

Opt-in confirmation: "Reply HELP for help, STOP to cancel. Msg & data rates may apply." — required
Recurring promotional: "Reply STOP to opt out" — required quarterly minimum; carrier-recommended every send
Transactional: Not required by TCPA but carriers expect it; include for safety

United States — A2P 10DLC

What it is

Application-to-Person 10-Digit Long Code registration, run by The Campaign Registry (TCR). Required for businesses sending SMS through 10DLC numbers (regular long codes) since 2022. Carriers (T-Mobile, AT&T, Verizon) enforce this; unregistered traffic gets throttled or blocked.

Registration components

Brand registration

Legal entity name, EIN, business type
Trust score assigned (Standard or Verified)
Higher trust = better throughput, lower fees

Campaign registration (one per use case)

Use case: Marketing, Account Notification, Customer Care, Public Service, Higher Education, Polling and Voting, 2FA, Delivery Notification, etc.
Sample message text (must match what you actually send)
Opt-in flow description and screenshot
Opt-out language
Help message language
Volume estimate

Phone number assignment to campaigns

Throughput tiers (varies by carrier and trust score)

Trust score + use case	Throughput
Verified brand, marketing	75–100+ msg/sec
Standard brand, marketing	4–10 msg/sec
Unregistered	0.1 msg/sec or blocked

Common rejections

Sample message text doesn't match actual sends
Opt-in flow screenshot doesn't show required disclosure language
"SHAFT" content (Sex, Hate, Alcohol, Firearms, Tobacco) without explicit use case
Generic or vague campaign descriptions

Process time: 1–7 business days. Plan for this in launch timelines.

Explicit opt-in: clear affirmative action (no pre-checked boxes)
Specific: opt-in must be for marketing SMS specifically, separate from generic ToS
Informed: data subject must know who's processing and why
Freely given: can't be bundled with service access

Mandatory provisions

Sender identity in every message
Easy opt-out in every message
Right to access data (DSARs)
Right to deletion
Records of consent kept for the duration of processing + statute of limitations

Penalty exposure

GDPR fines up to €20M or 4% of global revenue, whichever is higher.

Canada — CASL

Express consent: explicit opt-in (same standard as US TCPA express written consent)
Implied consent: existing business relationship within 24 months — limited use, expires

Every message must include

Sender identification (legal name + any operating names)
Mailing address
Phone, email, or website contact
Unsubscribe mechanism that works within 10 business days

Penalty exposure

Up to CAD $10M per violation. Enforced by the CRTC.

Australia — Spam Act 2003

Express or inferred consent (inferred has narrow application)
Sender ID required
Functional unsubscribe required
Enforced by ACMA

Multi-jurisdictional programs

If you send across US + EU + Canada simultaneously:

Default to the strictest standard across all jurisdictions (US TCPA express written consent + GDPR explicit opt-in)
Track consent jurisdiction per subscriber
Default quiet hours to recipient-local 9am–8pm
Include all required identifiers in every message

Audit-ready compliance checklist

[ ] A2P 10DLC registration complete (US, if applicable)
[ ] Opt-in flow includes all required disclosures, adjacent to phone field
[ ] Disclosure text matches A2P registered sample messages
[ ] Opt-in event captures: timestamp, IP, page URL, exact disclosure shown
[ ] STOP/HELP keywords honored across all variants
[ ] Quiet hours enforced at platform level (recipient-local time)
[ ] Privacy policy includes SMS section
[ ] Terms of service include SMS terms
[ ] Consent records retained per applicable law (typically 4+ years US, longer EU)
[ ] Process for handling DSARs (EU) and consent revocation
[ ] Sender identity in every message
[ ] Compliance footer on every promotional message (recommended) or quarterly minimum (required)
[ ] Test STOP/HELP from a real phone number quarterly to verify it still works

Platforms

platforms.md

SMS Platform Reference

Deep-dive on the major SMS marketing platforms — features, pricing, A2P 10DLC support, and integration paths.

> Pricing is approximate and changes regularly. Always confirm at the vendor's site before committing.

Klaviyo SMS

Best for: DTC ecom brands already using Klaviyo for email.

Key features

Native integration with Klaviyo email and segmentation
Shared subscriber profile across email + SMS
Built-in A2P 10DLC registration
Flow builder shared with email flows
Conversational SMS (two-way) supported

Pricing

Bundled with Klaviyo plans, billed per SMS credit
US: ~$0.0075–$0.015 per SMS; MMS ~$0.04
Free tier: 150 SMS credits/month on lower email tiers

Integration paths

Direct Shopify, WooCommerce, BigCommerce, Magento integration
API for custom platforms
MCP server available

Compliance

A2P 10DLC registration handled in-platform
Toll-free and short code provisioning available (short code adds $1,000+/mo)
Quiet hours enforced per recipient time zone (configurable)

Watch out for

Email + SMS combined billing can spike fast on large lists
Short code costs are real overhead; only worthwhile for 100K+ active SMS subscribers

Postscript

Best for: Shopify-native DTC brands wanting SMS-specific tooling and onboarding support.

Key features

Deep Shopify integration (the deepest of any SMS platform)
Strong abandoned cart and browse abandonment automations
AI Reply (auto-reply trained on brand voice)
Conversational SMS / live agent
Audiences pulled from Shopify customer data

Pricing

Tiered plans: Starter (free, 1K msgs/mo), Growth ($100+/mo), Professional, Enterprise
Pay-per-send adds on top: ~$0.015 per SMS, ~$0.04 per MMS

Integration paths

Shopify-first; limited support for non-Shopify
API + webhooks available

Compliance

A2P 10DLC handled in-platform
Strong opt-in compliance tools (popup builder, keyword opt-in)
Quiet hours enforced

Watch out for

Steep cost increase past Starter tier
Less useful if you're not on Shopify

Attentive

Best for: Mid-market and enterprise DTC brands wanting full-service SMS.

Key features

Full-service: dedicated CSM, copy support, strategy
Conversational SMS at scale
Concierge sales-via-SMS
Strong analytics and attribution
Identity resolution (matching anon site visitors to phone numbers)

Pricing

Custom contracts; typically $1K–$10K+/mo + per-send fees
Annual contracts standard
Pricing rarely makes sense for <50K SMS subscribers

Integration paths

Shopify, BigCommerce, Salesforce Commerce Cloud, custom
Robust API

Compliance

Full A2P 10DLC managed
Best-in-class compliance tooling and audit support
Short code provisioning included on most plans

Watch out for

Contract terms can lock you in for 12+ months
Overkill for early-stage brands

Twilio

Best for: Custom builds, transactional SMS, B2B SaaS embedding SMS into products, developers.

Key features

Raw SMS API
Pay-per-send pricing, no platform fees
Massive global coverage (200+ countries)
Programmable Voice, WhatsApp Business, RCS available alongside
Studio (visual flow builder) for non-code automation

Pricing

US 10DLC SMS: $0.0079 per message
US toll-free SMS: $0.0079 per message
US short code SMS: $0.0079 per message + $1,000/mo lease
MMS: ~$0.02
Carrier surcharges layered on top (~$0.005 per US 10DLC)
A2P 10DLC registration: ~$15 brand + $10/mo per campaign

Integration paths

API-first (REST + SDKs in Node, Python, Ruby, Go, etc.)
No native ecom integrations — you build them

Compliance

A2P 10DLC registration in-platform but you do the work
TwilioSendGrid (separate product) handles email-side compliance
Quiet hours and STOP/HELP handling must be implemented by you

Watch out for

You're responsible for compliance — no hand-holding
No native segmentation, deliverability dashboards, or marketing UI
Best paired with Customer.io, Segment, or a custom orchestration layer

Brevo (formerly Sendinblue)

Best for: EU-based brands, email + SMS combo, SMB-friendly.

Key features

Combined email + SMS + WhatsApp on one platform
EU-headquartered, GDPR-native
Generous free tier for email; SMS pay-per-send
Marketing automation flows
CRM included

Pricing

Free tier: 300 emails/day; SMS pay-per-send
US SMS: ~$0.015 per message
EU SMS: varies by country, ~€0.04–€0.07

Integration paths

Direct integrations: Shopify, WooCommerce, WordPress, Magento
API + Zapier
MCP server available

Compliance

GDPR + ePrivacy built-in
A2P 10DLC for US (less polished than dedicated US platforms)

Watch out for

US SMS features lag behind Klaviyo/Postscript
Best if you're EU-first or already on Brevo for email

SimpleTexting

Best for: SMB, services businesses, simple campaign blasts, low-volume.

Key features

Easy-to-use UI
Keyword opt-in for grassroots list building
Built-in landing pages for opt-in
Simple automation

Pricing

Plans start ~$30/mo for 500 credits, scaling up
US SMS only

Integration paths

Zapier, Make, native to a few apps
API available but basic

Compliance

A2P 10DLC handled
TCPA tooling

Watch out for

Limited automation depth vs Klaviyo/Postscript
Best for low-complexity, low-volume use cases (gyms, salons, real estate)

Plivo

Best for: Custom SMS builds where per-send cost matters; Twilio-style API at a lower price point.

Key features

Direct Twilio competitor with similar surface area
Powerpack for bulk sending with sticky sender across number pools
A2P 10DLC handled in-platform
WhatsApp, voice available alongside SMS
SDKs for major languages

Pricing

US 10DLC SMS: ~$0.0055/msg (typically 20–30% under Twilio)
US short code SMS: similar + monthly lease
MMS: ~$0.02
Phone number rental: ~$0.80/mo local, ~$1/mo toll-free

Integration paths

API-first (REST + SDKs)
No native ecom integrations — you build them

Compliance

A2P 10DLC managed in-platform
Compliance plumbing (STOP/HELP, quiet hours) is your responsibility — same model as Twilio

Watch out for

Smaller ecosystem than Twilio (fewer ancillary products, integrations, community resources)
WhatsApp tooling less mature

AudienceTap

Best for: DTC brands wanting AI-forward creative tooling or on-pack QR opt-in as a primary acquisition channel.

> Newer platform — verify current capabilities, pricing, and API surface before committing.

Key features

SMS + email on one platform (similar combined model to Klaviyo)
AI creative generation (SMS copy, subject lines, image variants)
On-pack QR code opt-in: insert cards in shipped orders that drive SMS list growth
Shopify, BigCommerce, headless commerce integrations
A2P 10DLC managed in-platform
Identity resolution and segmentation

Pricing

Tiered by subscriber count + send volume
Per-send pricing comparable to other DTC SMS platforms

Integration paths

API access on Growth+ tiers
Direct ecom integrations
Webhooks for events

Compliance

A2P 10DLC handled in-platform
TCPA tooling — verify enterprise-scale depth before committing for large lists

Watch out for

Newer entrant — fewer reference customers, less battle-tested at high volume than incumbents
Some features rolled out recently — confirm what's GA vs beta before relying on them

Customer.io

Best for: B2B SaaS, behavior-based automation, multi-channel orchestration (email + SMS + push).

Key features

Trigger SMS off product events (signup, milestone, churn risk)
Powerful audience segmentation
Workflow builder
Real-time data sync via API/webhooks

Pricing

Plans start ~$150/mo, scaling with profile count
SMS via Twilio integration or native (varies)

Integration paths

API-first
Direct integrations with Segment, Heap, Mixpanel, etc.

Compliance

A2P 10DLC via Twilio if using native integration
Granular subscription/consent management

Watch out for

Less ecom-tailored than Klaviyo/Postscript
Best for product-led SaaS or apps with deep event tracking

Quick selection table

Stack / Goal	Recommended	Why
Shopify ecom, already on Klaviyo	Klaviyo SMS	One platform, one subscriber profile
Shopify ecom, SMS-first focus	Postscript	Deepest Shopify + SMS-specific features
Mid-market ecom, want concierge support	Attentive	Full-service team + tooling
Custom platform, B2B SaaS, transactional	Twilio	API-first, full control
Custom build, cost-sensitive	Plivo	~20–30% cheaper than Twilio per send
DTC wanting AI creative or on-pack QR opt-in	AudienceTap	AI-forward; insert-card opt-in is unique
EU-based SMB	Brevo	GDPR-native, EU-friendly pricing
Local services SMB, simple campaigns	SimpleTexting	Easy UI, low overhead
Product-led SaaS with event tracking	Customer.io	Behavior-based triggers

A2P 10DLC: what your platform should handle

Whatever you pick, confirm your platform handles:

[ ] Brand and campaign registration with TCR
[ ] Sample message text aligned with what you actually send
[ ] Opt-in flow documentation submitted to carriers
[ ] Trust score visibility (and a path to improve it)
[ ] Throughput appropriate to your list size and send frequency
[ ] STOP/HELP keyword handling
[ ] Quiet hours by recipient time zone
[ ] Suppression list management
[ ] Consent record retention with timestamps

All major platforms above handle these. Twilio does the lowest-level work and pushes more responsibility onto you.

Sequence Templates

sequence-templates.md

SMS Sequence Templates

Full copy templates with character counts, timing, and segmentation logic for every major SMS flow.

> Character counts shown assume GSM-7 encoding. Emojis force UCS-2 (70 chars/segment instead of 160). All templates use [Brand], [FirstName], and [short.link] as substitution tokens.

Welcome / Opt-In Confirmation

Send 1 — Immediate (after opt-in)

B0 ~155 chars / 1 segment (just). Footer required on first send.

Send 2 — 24 hours later (optional)

B1 ~108 chars / 1 segment.

Send 3 — 7 days later (optional, conditional on no purchase)

B2 ~107 chars / 1 segment.

Abandoned Cart (highest-ROI flow for ecom)

Send 1 — 30 minutes after abandon

B3 ~95 chars / 1 segment.

Send 2 — 4 hours after abandon (if no purchase)

B4 ~98 chars / 1 segment.

Send 3 — 24 hours after abandon (if no purchase, discount allowed)

B5 ~99 chars / 1 segment.

Notes:

Discount on Send 1 trains customers to abandon. Reserve for Send 2 or 3.
Exclude customers who abandoned <$X in cart value or repeat abandoners (gaming the discount).
Stop sequence on purchase, opt-out, or 48 hours elapsed.

Browse Abandonment

Send 1 — 1 hour after browse (single product or category)

B6 ~84 chars / 1 segment.

Notes:

Trigger only after meaningful browse signal (3+ product views or 2+ min on product page).
Exclude if a purchase happened on a different product.

Post-Purchase Flow

B7 ~95 chars / 1 segment.

Send 2 — Day of shipment

B8 ~92 chars / 1 segment.

Send 3 — Day of delivery

B9 ~88 chars / 1 segment.

B10 ~108 chars / 1 segment.

B11 ~99 chars / 1 segment.

Win-Back (Lapsed Customers)

Send 1 — 60-90 days after last purchase

B12 ~84 chars / 1 segment.

Send 2 — 14 days later (if no purchase)

B13 ~106 chars / 1 segment.

Send 3 — 14 days after Send 2 (final, if no purchase)

B14 ~130 chars / 1 segment.

Notes:

After Send 3 with no engagement, suppress for 90 days minimum.
After two full win-back cycles with no engagement, sunset (remove from active list).

Promotional / Campaign Sends

Flash sale (single send)

B15 ~94 chars / 1 segment.

Limited drop / launch

B16 ~115 chars / 1 segment.

Holiday / BFCM (2-send sequence)

Send 1 — Day of launch:

B17 ~92 chars / 1 segment.

Send 2 — Day of (or evening, expiration push):

B18 ~73 chars / 1 segment.

Transactional / Account Notifications

Order confirmation

B19

Shipping update

B20

Delivery confirmation

B21

Auth code (2FA)

B22

Account alert

B23

Re-Engagement / Reactivation (Subscribers Who've Gone Cold)

For SMS subscribers who haven't engaged with any send in 60+ days.

Send 1 — Soft reactivation

B24 ~80 chars / 1 segment.

Send 2 — Confirm interest (if no engagement)

B25 ~98 chars / 1 segment.

After no reply: suppress for 60 days, then remove from active list. This protects opt-out rate metrics and reduces wasted spend.

Replenishment (Consumables Ecom)

For products with predictable usage cycles (skincare, supplements, coffee, pet food).

Send 1 — At expected reorder window (e.g., 28 days for a 30-day supply)

B26 ~73 chars / 1 segment.

Send 2 — 7 days later (if no purchase)

B27 ~92 chars / 1 segment.

VIP / Loyalty Members

Higher frequency, exclusive offers, early access — different cadence rules apply but quiet hours and STOP still required.

Early access

B28 ~72 chars / 1 segment.

Loyalty milestone

B29 ~95 chars / 1 segment.

Segmentation rules across all flows

Suppress customers in active sequences from promotional sends (no double-tap)
Suppress opted-out subscribers from everything (platform handles this)
Frequency cap: max 4–6 marketing sends/week per subscriber (lower for newer subscribers)
Quiet hours: 9am–8pm recipient-local time
Cool-off: After a discount-driven purchase, suppress promotional sends for 14 days

whatsapp.md

WhatsApp Business Platform Reference

Adapted from a contribution by @Inflimity (PR #516).

> Platform facts below are as of 2026-10 and sourced from Meta's developer docs (links in Sources). Meta changes pricing and limits often. Check the pricing page before quoting costs to a client.

When WhatsApp Fits vs SMS

WhatsApp is the default messaging app in most of Latin America, Europe, Africa, the Middle East, and South and Southeast Asia. In the US and Canada, SMS still reaches more people.

Situation	Better fit	Why
Customers mostly in LATAM, EMEA, India, SEA	WhatsApp	It's where conversations already happen
Customers mostly in the US	SMS	Meta does not currently deliver marketing templates to US (+1) numbers
Rich product messages (images, buttons, lists)	WhatsApp	Native interactive formats, no MMS surcharge
Two-way sales or support conversations	WhatsApp	Threaded chat, reply buttons, human handoff
Paid social is a major acquisition channel	WhatsApp	Click-to-WhatsApp ads open a free window
Simple one-way alerts, auth codes, US-heavy list	SMS	Simpler setup, universal reach
Multi-country program	Both	WhatsApp where adoption is high, SMS as fallback

Ask first: where are the customers? If more than half are in the US, WhatsApp marketing is a support or transactional layer at best until Meta lifts the US marketing restriction.

App vs Platform

WhatsApp Business app: free, manual, one phone or a few linked devices. Fine for a solo operator answering chats. Not built for automation or large broadcasts.
WhatsApp Business Platform (Cloud API): programmatic sending, templates, webhooks, automation. You access it directly through Meta or through a Business Solution Provider (BSP).

BSPs include messaging APIs (Twilio, Infobip, Sinch, MessageBird/Bird), WhatsApp-focused tools (Wati, Interakt, AiSensy), chat automation tools (ManyChat, respond.io), and lifecycle platforms that added WhatsApp (Klaviyo, Brevo, Customer.io). Pick based on your existing stack, the markets you send to, and whether you need a no-code flow builder. All of them pass through Meta's per-message fees; most add a markup or platform fee on top.

The 24-Hour Customer Service Window

Window opens when the customer messages you. It lasts 24 hours from their latest message. Each new customer message resets it.
Inside the window: you can send free-form messages (text, media, interactive buttons and lists) without pre-approval.
Outside the window: you can only send a pre-approved template. Free-form sends fail (error 131047, "Re-engagement message").

Design flows around this. A cart recovery message 1 hour after abandonment is almost always outside a window, so it must be an approved template.

Template Categories

Every template is one of three categories. Meta checks the category you pick.

Category	What qualifies	Examples
Marketing	Anything promotional, awareness, or retargeting	Offers, launches, back-in-stock, abandoned cart reminders, re-engagement
Utility	Non-promotional AND specific to the user's request or account (or critical to them)	Order confirmation, shipping update, appointment reminder, billing notice
Authentication	One-time passcodes only, using Meta's pre-built formats	Login codes, verification codes

Rules that trip people up:

Cart reminders are marketing, even when the user asked to be reminded. Meta's guidelines list "You left {{items}} in your cart" as a retargeting example.
Mixed content becomes marketing. An order update with a promo code, or a feedback survey with a discount, is a marketing template.
Auto-recategorization. Since April 9, 2025, a template submitted as utility that Meta judges to be marketing is approved as marketing. Meta also re-reviews approved templates and recategorizes them (usually with 1 day's notice, none for repeat misuse).
Appeals: you have 60 days from creation or a category change to request review.
Authentication templates can't contain URLs, media, or emojis.

Template anatomy: optional header (text, image, video, document), body with variables like {{1}}, optional footer (often the opt-out line), and optional buttons (quick reply, URL, phone, copy-code). Submit realistic sample values for every variable. Vague samples are a common rejection cause.

Opt-In and Opt-Out

Meta requires opt-in before you message someone. The opt-in should clearly tell the person they'll get messages from your business, and it must comply with local law (GDPR, LGPD, India's DPDP Act, TCPA, and so on). Meta allows a general business opt-in, but naming WhatsApp explicitly is the safer practice and what many laws effectively expect, so do it unless you have a reason not to.

You can collect it through a website form, checkout checkbox, SMS, IVR, in person, or inside a WhatsApp chat. Meta recommends separate opt-ins (or one opt-in that names the categories) for order updates vs offers.

Sample checkout opt-in (unchecked by default):

> [ ] Send me order updates and offers from Acme on WhatsApp. You can opt out anytime.

Opt-out handling:

Add a quick reply button like Stop promotions to every marketing template, or a footer like "Reply STOP to opt out"
When someone opts out, flag them in your CRM immediately and stop all marketing templates
Send one confirmation: "You're unsubscribed from Acme offers. Reply START to rejoin."
Keep sending utility messages they still need (order updates) if they opted in to those separately

An easy opt-out protects you. If the only way to stop your messages is the Block button, people will block, and blocks drive your quality rating down.

Quality Rating and Messaging Limits

Quality rating

Each phone number has a quality rating based on how recipients responded to your messages over the past 7 days: blocks, reports, and the reasons given ("Didn't sign up," "Spam," "No longer needed").

Rating	Meaning
Green (High)	Healthy, eligible to scale
Yellow (Medium)	Warning, negative feedback rising
Red (Low)	Number goes to Flagged status

If a Flagged number recovers to medium or high within 7 days, nothing changes. If it doesn't, your messaging limit drops one level.

Templates have their own quality ratings too. New or low-quality marketing and utility templates get paced (Meta holds part of a send to collect feedback first). Bad feedback pauses the template, and held messages fail.

Messaging limits

The messaging limit is how many unique users you can reach with template messages outside a service window in a rolling 24 hours. The limit is now shared across your whole business portfolio, not set per phone number, so one busy number can use up the allowance for all of them.

Tier	Unique users per 24h
Starting default	250
After verification or scaling	2,000
Next levels	10,000 → 100,000 → Unlimited

250 to 2,000: complete business verification, or deliver 2,000 high-quality template messages to unique users within 30 days
Above 2,000: automatic when you've used at least half your current limit in the last 7 days with high-quality messages across all numbers and templates. Upgrades land within about 6 hours.
Replies inside a service window don't count toward the limit

Per-user marketing limits

Meta also caps how many marketing templates one person receives from all businesses, based on their recent read rate. Blocked sends return error 131049. Wait at least 24 hours before retrying. A marketing message sent inside an open service window doesn't count toward this cap.

Warming up a new number

Get business verification done first. It makes the account eligible to scale toward 2,000, but Meta still approves or denies the increase after a quality review, so check the actual limit before scheduling sends
Send your first templates to recent, high-intent opt-ins (buyers from the last 30 days, people who messaged you)
Scale volume over 1-2 weeks as the number stays green
Spread big sends over hours instead of firing everything at once
Watch block reasons in WhatsApp Manager after every campaign

Message Formats

Format	Limits	Best for
Reply buttons	Up to 3 buttons, 20 chars each	Yes/no, pick a path, opt-out
List message	Up to 10 rows across up to 10 sections, row titles 24 chars	Product categories, booking slots, qualification
URL / call buttons (templates)	Opens a link or starts a call	Checkout, tracking, support line
Media header	Image, video, or document	Product shots, drops, receipts
Catalog / product messages	Pulls from a Meta commerce catalog	Browsing and buying in chat

Copy guidelines:

Keep each bubble to 1-3 short sentences (roughly under 60 words)
Use buttons instead of pasting raw URLs
WhatsApp formatting works: *bold*, _italic_, line breaks
One or two emojis are fine. Unlike SMS, they don't change cost
Name your brand in the first line of templates, since many users won't have your number saved

Pricing (as of 2026-10)

Meta moved from conversation-based pricing to per-message pricing on July 1, 2025. You pay per delivered message, at a rate set by message category and the recipient's country code.

Message type	How it's charged
Marketing template	Charged on every delivery, inside or outside a service window
Utility template	Charged outside a window. Inside an open window it was free from July 1, 2025 until October 1, 2026, when Meta began charging for it
Authentication template	Charged per delivery; check the current rate card for in-window treatment in your market
Service message (free-form reply)	Free from November 1, 2024. From October 1, 2026, each business phone number gets 1,000 free service messages a month (no rollover); after that, they're charged per message at the same rate as utility/authentication in that market, with no volume tiers
Meta Business Agent (Meta's AI agent)	Charged per token from August 1, 2026, about $2 per 1M tokens. Never free
Anything in a free entry point window	Free (see below)

Volume tiers: utility and authentication rates drop as monthly volume grows, measured across your whole portfolio per market. Tiers reset each calendar month. Marketing has no volume tiers, but the Marketing Messages API lets you set a max price per delivery.

Practical math: rates differ a lot by country. Marketing is the most expensive category in every market, often several times the utility rate. Pull current rates from Meta's rate cards (or your BSP's, which include their markup) and model cost per recovered order before launching a flow.

The October 2026 changes mean support conversations beyond the first 1,000 a month per number, and in-window order updates, now cost money. If your old business case assumed "replies are free," redo it.

Click-to-WhatsApp Ads

Click-to-WhatsApp (CTWA) ads run on Facebook and Instagram and open a WhatsApp chat with your business when tapped.

Free entry point window: when someone messages you from a CTWA ad or a Facebook Page call-to-action button and you reply within 24 hours, a free entry point window opens from the time you respond. Meta says it may stay open for up to 7 days (as of 2026-10). While it's open, Meta doesn't charge for marketing, utility, authentication, or service messages; Meta Business Agent messages are still charged. Check the window's actual expiry in your delivery data rather than assuming the maximum.

How to use it:

Hook the ad on a reason to chat: a quiz, sizing help, a quote, a code to claim
Pre-fill the user's first message: "Hi! I'd like my 15% welcome code."
Reply fast with buttons: 2-3 qualifying questions as reply buttons
Convert or hand off while the free window is open: checkout link, booking link, or a live rep
Ask for marketing opt-in in the chat so you can follow up with templates later

Playbooks

1. Abandoned cart recovery

Trigger: 45-60 minutes after abandonment, only for contacts with WhatsApp marketing opt-in
Type: marketing template (outside the window, and cart reminders are marketing by definition)
Exit: stop on purchase, opt-out, or 48 hours
Second touch (optional, 24 hours): only if the first wasn't read or clicked, and hold any discount until here

"I have a question" opens a service window. Route it to the support handoff below.

2. Welcome (after opt-in or CTWA)

Trigger: immediately after opt-in, or the first inbound message from an ad
Type: free-form if they just messaged you (window open), otherwise a marketing template

Each button routes to 2-3 product picks with a checkout link. Ask for marketing opt-in here if they came from an ad.

3. Re-engagement / win-back

Audience: opted-in customers with no purchase in 60-90 days
Type: marketing template
Frequency: 1-2 marketing sends per month to this segment. More gets you blocks and per-user limit errors

"Not now" suppresses them for 30 days. "Stop promotions" opts them out.

4. Support handoff

Trigger: a help button, a keyword like "agent," or the bot failing to match twice
Type: service messages (window open). These are charged from October 1, 2026, so resolve in as few messages as you can

Pass the cart or order context to the agent so the customer doesn't repeat themselves. Outside staffed hours, say when a person will reply and offer an FAQ list. If the reply goes past 24 hours, you'll need a utility template to answer.

Sources

All accessed 2026-10.

Pricing: https://developers.facebook.com/documentation/business-messaging/whatsapp/pricing
Pricing updates for service and utility messages (Oct 2026): https://developers.facebook.com/documentation/business-messaging/whatsapp/pricing/non-template-messages
Messaging limits: https://developers.facebook.com/documentation/business-messaging/whatsapp/messaging-limits
Phone number quality rating: https://www.facebook.com/business/help/896873687365001
Template categorization: https://developers.facebook.com/documentation/business-messaging/whatsapp/templates/template-categorization
Template pacing: https://developers.facebook.com/documentation/business-messaging/whatsapp/templates/template-pacing
Per-user marketing limits (incl. US restriction): https://developers.facebook.com/documentation/business-messaging/whatsapp/templates/marketing-templates/per-user-limits/
Opt-in: https://developers.facebook.com/documentation/business-messaging/whatsapp/getting-opt-in
Reply buttons: https://developers.facebook.com/documentation/business-messaging/whatsapp/messages/interactive-reply-buttons-messages
List messages: https://developers.facebook.com/documentation/business-messaging/whatsapp/messages/interactive-list-messages
Click-to-WhatsApp ads: https://developers.facebook.com/documentation/ads-commerce/marketing-api/ad-creative/messaging-ads/click-to-whatsapp

Exported from Marketing Skills on 2026-10-12

sms

SMS Marketing

Before Starting

1. Business Type

2. Current State

3. Compliance Posture

4. Goal

When SMS Beats Email

WhatsApp

Compliance — Read First

US — TCPA (Telephone Consumer Protection Act)

US — A2P 10DLC Registration (required since 2022)

EU/UK — GDPR-derived consent

Canada — CASL

Phone Number Types (US)

Core Principles

1. Every send has a real cost

2. Opt-in is your most valuable asset

3. Each message must justify itself

4. Brevity + clarity

5. One CTA, one link

6. Sender identity, every send

SMS Sequence Types

Welcome / Opt-In Confirmation (immediate)

Abandoned Cart (highest-ROI flow for ecom)

Browse Abandonment

Post-Purchase

Win-Back (lapsed)

Promotional / Campaign Sends

Transactional (separate compliance bucket)

SMS Copy Guidelines

Structure

Length

Voice

Personalization

Platform Selection

Measurement

Key Metrics

What to track in analytics

What to A/B test

Output Format

Task-Specific Questions

Common Mistakes

Tool Integrations

Related Skills

References

Compliance

SMS Compliance Reference

United States — TCPA

What it is

Consent tiers

Express written consent requirements

Opt-in disclosure template (compliant)

Quiet hours

STOP/HELP handling

Sample TCPA-compliant footer language by sequence type

United States — A2P 10DLC

What it is

Registration components

Throughput tiers (varies by carrier and trust score)

Common rejections

EU / UK — GDPR + ePrivacy Directive

Consent requirements

Mandatory provisions

Penalty exposure

Canada — CASL

Consent

Every message must include

Penalty exposure

Australia — Spam Act 2003

Multi-jurisdictional programs

Audit-ready compliance checklist

Platforms

SMS Platform Reference

Klaviyo SMS

Key features

Pricing

Integration paths

Compliance

Watch out for