/sms

name: sms
description: When the user wants to plan, build, or optimize SMS or MMS 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," or "SMS vs email." For email sequences, see emails. For SMS copy framing, see copywriting. For opt-in popups that capture phone numbers, see popups.
metadata:
  version: 1.0.0

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)

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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.

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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)

1. **Express written consent** required for marketing SMS. Implied consent doesn't count. 2. **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. 3. **Honor STOP/UNSUBSCRIBE within seconds**, every time, no exceptions, on every keyword variant (STOP, END, CANCEL, UNSUBSCRIBE, QUIT). 4. **Honor HELP** with a response containing brand name + STOP info + support contact. 5. **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. 6. **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.

EU/UK — GDPR-derived consent

• 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](references/compliance.md).

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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