sms

name	sms
description	SMS and MMS marketing — opt-in mechanics, TCPA/carrier compliance, flow design (welcome, abandoned cart, post-purchase, win-back, replenishment), segment/character budgeting, cadence and frequency caps, platform selection, and revenue-per-send measurement. Use for "SMS marketing", "text message campaign", "SMS sequence", "abandoned cart text", "SMS compliance", "A2P 10DLC", "TCPA", "short code vs toll-free", "MMS campaign", "Klaviyo SMS", "Postscript", "Attentive", "Twilio", or "SMS vs email". For email sequences use email-sequence or emails; for phone-number capture on-site use popup.
allowed-tools	Read, Write, Glob, Grep

SMS Marketing

SMS earns the right to interrupt only because someone opted in. Every send costs money, spends attention, and carries legal exposure — so if the message could wait 24 hours, it is an email.

When this skill activates

Implicit: planning, writing, or fixing an SMS/MMS program — welcome and opt-in confirmation texts, abandoned-cart and browse-abandonment flows, post-purchase and replenishment, win-back, promotional/flash sends, transactional and auth messages, opt-in disclosure copy, STOP/HELP handling, quiet-hours and frequency policy, "should we do SMS at all", "our opt-out rate is spiking". Explicit: "Use the sms skill to [task]." Routed from: /mk:email sms (the sms action names this skill directly), the email-specialist agent (email + SMS owner), and .claude/workflows/crm-workflow.md lifecycle stages that fire SMS alongside email.

Scope

Covers:

• SMS/MMS flow design: trigger, delay, exit condition, copy, and segmentation per send.
• Opt-in mechanics and disclosure copy; STOP/HELP keyword handling; quiet hours.
• US compliance posture — TCPA consent tiers, A2P 10DLC registration, carrier expectations — plus non-US pointers.
• Segment/character budgeting (GSM-7 vs UCS-2), MMS trade-offs, cost-per-send discipline.
• Cadence, frequency caps, suppression, and sunset rules.
• Platform selection and the SMS-vs-email channel decision.
• Measurement: opt-in rate, CTR, revenue per send, opt-out rate per send.

Does NOT cover:

• Lifecycle/drip email nurture → [[email-sequence]].
• One-shot broadcast email campaigns to an owned list → [[emails]].
• Cold outbound to people with no relationship → [[cold-email]]. Cold SMS to non-consented numbers is out of scope entirely — it is not a copy problem, it is a consent problem.
• On-site phone-number capture popups and their design → [[popup]]; signup-flow field capture → [[signup]].
• Long-form copy the SMS links to → [[copywriting]].
• Attribution plumbing and UTM/event instrumentation → [[analytics]].

Before writing

Load plans/marketing-context.md first (ICP, positioning, brand voice, forbidden words). Then confirm only what it does not answer:

1. Geography — US, EU/UK, Canada, or mixed. This changes the compliance approach entirely, not marginally.
2. A2P 10DLC status (US) — registered or not. Unregistered 10DLC traffic gets throttled or filtered; messages can show "delivered" and never arrive.
3. Number type — short code, toll-free, or 10DLC long code.
4. List state — email list size, SMS opt-in rate, current opt-out rate, revenue per send if any.
5. Business model — DTC/ecom, mobile app, B2B SaaS, services. SMS economics differ sharply.
6. Goal — revenue (promo, cart recovery, post-purchase), activation (welcome, milestone nudges), or transactional (order, auth, alerts).

If compliance blockers exist, surface them before designing anything. A beautiful flow on an unregistered number is wasted work.

When SMS beats email

Use case	Channel	Why
Abandoned cart recovery	SMS first	Read within minutes; email recovery lags by hours
Order / shipping updates	SMS	Wanted immediately, on the phone
Flash sale, limited drop	SMS	Urgency channel
Auth codes / 2FA	SMS or app	Latency-sensitive
Welcome series	Email primary, SMS layer	Email carries the long-form content
Educational nurture	Email	Too much text for SMS; segment costs stack
Newsletter	Email	Wrong channel for SMS
Win-back	Both	SMS for the nudge, email for the offer detail
Post-purchase upsell	SMS	Rides purchase momentum

Rule: if it could wait 24 hours, send it by email.

Compliance — read before designing

Compliance is the foundation, not a footer. The guidance below is US-centric — it reflects US federal law and US carrier practice as described by the upstream source, and does not transfer to the EU/UK, Canada, or Australia, each of which has its own consent regime (see references/compliance.md). This skill states operational practice, not legal advice, and does not determine whether a specific program is lawful.

US — TCPA, the load-bearing rules:

1. Express written consent is required for marketing SMS. An existing business relationship is not consent.
2. Disclosure at the point of opt-in must state: program/brand name, frequency expectation, STOP and HELP instructions, "Msg & data rates may apply", and a link to terms and privacy. Place it adjacent to the phone field, not in a footer.
3. Consent is not a condition of purchase — say so in the disclosure.
4. Honor STOP within seconds, every time, on every variant (STOP, END, CANCEL, UNSUBSCRIBE, QUIT, STOPALL, OPTOUT). Never require a login or a website visit to opt out.
5. Honor HELP with brand name, support contact, and STOP instructions.
6. Quiet hours — federal floor is 8am–9pm recipient-local; several US states and carrier guidance are stricter. Default to 9am–8pm recipient-local. Time zone inferred from area code is unreliable (people move); confirm the platform handles it.
7. Keep auditable consent records — timestamp, source, and the exact disclosure text shown.

US — A2P 10DLC. Sending marketing SMS over a 10-digit long code requires brand + campaign registration through The Campaign Registry via your platform. Registered sample message text must match what you actually send; mismatches get campaigns flagged. Register before you plan a launch date.

Transactional messages (order status, shipping, auth codes) sit in a separate consent bucket when directly tied to a transaction the user initiated — but they are still subject to registration and carrier rules, and must not carry marketing content riding along.

Full jurisdiction detail, opt-in disclosure template, and STOP/HELP response templates: references/compliance.md.

PII: phone numbers are PII. Per .claude/workflows/automation-rules.md §4, never write real subscriber numbers, names, or addresses into plans/marketing/ files or summaries — design flows against tokens ([FirstName], [short.link]) and keep subscriber data in the platform.

Numbers and throughput (US)

Type	Throughput	Relative cost	Fits
Short code (5–6 digit)	Highest	High monthly + setup	High-volume marketing; carrier-vetted, highest trust
Toll-free (1-8XX)	Moderate	Low monthly	Mid-volume B2C marketing and support
10DLC long code	Low to moderate, trust-score dependent	Lowest monthly	SMB, conversational, transactional — requires A2P registration

Rough sizing: list under ~10K → 10DLC; ~10K–100K → toll-free; 100K+ → short code. Confirm current pricing and throughput with the platform; both move.

Message structure and segment budget

Every message: sender ID → hook → value → single CTA + short link → compliance footer. Recipients cannot see a "from" name — the brand must be inline ("From Acme: ...").

• 160 characters (GSM-7) = 1 segment. Aim here.
• Any emoji, accented character, or curly quote forces UCS-2 → 70 characters per segment. One smart quote pasted from a doc can double the bill on a 100K send.
• 161–306 chars = 2 segments, billed as two. Acceptable when the message earns it.
• MMS (image + longer body) costs several times an SMS. Reserve for high-impact moments.
• One CTA, one link, always shortened and UTM-tagged.
• Compliance footer — required on the opt-in confirmation and on a recurring basis thereafter; carrier guidance favors every promotional send.

Voice: conversational, no marketing-speak, no formatting, no subject-line thinking. Emoji sparingly and deliberately (they cost characters). ALL CAPS only for codes. First-name personalization when real; never fake intimacy.

Flows and cadence

Priority order for DTC/ecom, highest return first: abandoned cart → welcome/opt-in → post-purchase → browse abandonment → win-back → replenishment → promotional sends.

• Welcome / opt-in confirmation — immediate confirmation + the promised incentive, compliance footer mandatory. Optional reminder at 24h, last-chance at 7 days.
• Abandoned cart — 30 min ("you left something"), 4h (soft urgency / social proof), 24h (discount, only if margin allows). Never discount on send 1 — it trains abandonment. Exit on purchase or opt-out.
• Browse abandonment — one send ~1h after a meaningful browse signal (multiple product views or sustained time on page), not on a single pageview.
• Post-purchase — confirmation, shipment, delivery (transactional), then review prompt ~2 days after delivery and cross-sell ~14 days (marketing consent required).
• Win-back — 60–90 days after last purchase (no offer), +14 days (offer), +14 days (final, with an explicit opt-out invitation). Then suppress 90 days; sunset after two failed cycles.
• Replenishment — fire just before the expected reorder window for consumables; one nudge, one reminder.
• Re-engagement — for subscribers cold 60+ days: one soft send, then a "reply YES to stay" confirmation, then suppress and remove. Protects opt-out rate and spend.
• Promotional — 1–2 sends per campaign. Stagger against the email calendar; never same-day double-tap.

Frequency caps: 4–6 marketing sends per week per subscriber maximum, lower for new subscribers. Suppress anyone in an active automated flow from promotional sends. Cool off promotional sends for ~14 days after a discount-driven purchase. Throttle bulk sends — burst traffic triggers carrier filtering.

Full copy templates with character counts and exit conditions: references/sequence-templates.md.

Platform selection

Stack / goal	Pick	Why
DTC ecom already on Klaviyo email	Klaviyo SMS	One subscriber profile across email + SMS
Shopify ecom, SMS-first	Postscript	Deepest Shopify integration, strong cart flows
Mid-market ecom wanting full service	Attentive	Managed strategy + compliance tooling; contract-heavy
Custom build, transactional, B2B SaaS	Twilio	API-first, full control, you own compliance plumbing
Cost-sensitive custom build	Plivo	Twilio-shaped API at lower per-send cost
EU-first SMB, email + SMS combined	Brevo	GDPR-native, EU pricing
Local services SMB, simple blasts	SimpleTexting	Low complexity, keyword opt-in
Product-led SaaS with event tracking	Customer.io	Behavior-triggered SMS alongside email/push

Whatever the pick, confirm it handles: A2P registration, STOP/HELP variants, recipient-local quiet hours, suppression lists, and timestamped consent records. Detail in references/platforms.md.

ClauKit has no SMS-platform MCP wrapper. Per .claude/workflows/automation-rules.md §6, run the manual path: this skill generates the flow spec, copy, and segment plan; the user builds it in the platform and pastes performance data back for analysis.

Measurement

Track per send and per flow:

• Opt-in rate — share of email subscribers who join SMS. Quality beats volume; a small consented list outperforms a large scraped one.
• CTR — relevance signal; SMS clicks materially outperform email, which is why weak targeting hides for a while.
• Conversion rate and revenue per send (RPS) — the only numbers that justify the channel, because every send has a hard cost.
• Opt-out rate per send — the fatigue alarm. Watch the trend, not one send; a rising line means cadence or targeting is wrong.
• Cost per send and total program cost against revenue attributed.
• List growth rate — net of opt-outs.

UTM-tag every link (utm_source=sms&utm_medium=sms&utm_campaign=<campaign>) and set attribution up front — an unattributed SMS program cannot defend its budget. Benchmark ranges reported by SMS vendors are in references/platforms.md; treat them as directional, not as targets to promise.

Test queue: send time (afternoon vs evening, recipient-local), copy length (SMS vs MMS), discount amount and which send it lands on, personalization token present vs absent, CTA wording. One variable at a time.

Pre-send gate

Refuse to hand over a send plan until every line passes:

• Consent basis identified for every segment in the send (marketing vs transactional).
• A2P 10DLC registered (US) and registered sample text matches the actual copy.
• Opt-in disclosure live, adjacent to the phone field, matching what was registered.
• STOP/HELP variants handled and verified from a real handset.
• Quiet hours enforced recipient-local at the platform.
• Sender identity inline in every message; compliance footer where required.
• Suppression applied: opt-outs, active-flow members, recent purchasers.
• Segment count and cost per send calculated (check for stray emoji/curly quotes).
• Short links UTM-tagged; conversion attribution live.
• No real subscriber PII written into any plan file.

Common mistakes

1. Sending before A2P 10DLC registration — messages get filtered while dashboards report success.
2. Treating SMS as email — daily blasts spike opt-outs and kill the list.
3. Discounting on the first abandoned-cart send — teaches customers to abandon.
4. No brand name in the message body — recipients see a number, not a sender.
5. Ignoring quiet hours and recipient time zones.
6. Unverified STOP/HELP handling — non-negotiable and easy to break during a platform migration.
7. Emoji everywhere — halves the segment size and doubles cost.
8. Registered sample messages that do not match real sends.
9. No conversion attribution — the channel cannot justify its cost.
10. Unthrottled bulk sends — carrier filtering.

Key concepts

• Consent is the asset — the list's value is the consent record behind it, not its row count. Everything else in this skill assumes valid, documented opt-in.
• Every send has a hard cost — unlike email, waste is billed. Cost pressure is what forces real segmentation.
• Segment budget — the character count is a billing unit, not a style guide; encoding choices (emoji, smart quotes) change the price.
• Right to interrupt — the test for any message: would the recipient be glad they got this text? If not, it goes to email or nowhere.
• Immediacy premium — SMS is worth its cost only where speed changes the outcome (cart, drop, delivery, auth).
• Opt-out rate as a fatigue meter — the earliest reliable signal that cadence or targeting has broken, well before revenue drops.
• Transactional/marketing boundary — a transactional message that carries a promotion becomes a marketing message, with the consent requirements that implies.

Output

Routed through /mk:email sms, which writes under plans/marketing/<campaign>/emails/:

• plans/marketing/<campaign>/emails/sms-<flow>.md — per flow: trigger, delay, exit condition, copy with segment count, CTA/link, segmentation and suppression rules.
• plans/marketing/<campaign>/emails/sms-compliance.md — consent basis per segment, opt-in disclosure copy, STOP/HELP response text, quiet-hours policy, and the pre-send gate with each line resolved.

For SMS-only work invoked outside /mk:email, plans/marketing/<campaign>/sms/<flow>.md is the equivalent path. Either way: copy templates and token placeholders only — no subscriber phone numbers, names, or addresses in the file.

Or inline: a channel-fit recommendation, a compliance blocker review, or a diagnosis of an underperforming flow.

Cross-references

• plans/marketing-context.md — required hub (ICP, positioning, brand voice, forbidden words)
• .claude/workflows/automation-rules.md — §4 PII handling (phone numbers are PII), §6 manual fallback, §7 output conventions
• .claude/workflows/marketing-rules.md — copy quality gates, anti-patterns
• .claude/workflows/crm-workflow.md — lifecycle stages that trigger SMS alongside email
• [[emails]] — one-shot broadcast campaigns to an owned list
• [[email-sequence]] — lifecycle/drip email nurture; SMS layers on top of it, it does not replace it
• [[cold-email]] — cold outbound (email); cold SMS is not a supported pattern
• [[popup]] — on-site phone-number capture, where the opt-in disclosure has to live
• [[signup]] — signup-flow field capture and consent checkbox placement
• [[copywriting]] — the landing pages and long-form copy SMS links to
• [[analytics]] — attribution, UTM plumbing, revenue-per-send reporting
• [[launch]] — coordinating promotional SMS with a launch calendar
• references/compliance.md · references/sequence-templates.md · references/platforms.md
• .claude/skills/marketing/README.md — full kit overview

Provenance

Imported from coreyhaines31/marketingskills (skills/sms/, MIT, © 2025 Corey Haines) and adapted for KitForge: KitForge frontmatter and wikilink cross-references, product-marketing context file replaced by plans/marketing-context.md, output wired to the /mk:email sms path, PII handling bound to .claude/workflows/automation-rules.md §4, upstream tools-registry/MCP columns and pointers to skills ClauKit lacks (ab-testing, churn-prevention, lead-magnets) dropped, unsourced settlement-cost claims removed, and US-specific rules explicitly marked as US-specific. The three source reference files are ported with the same adaptation.