SMS marketing has an open rate email can't touch — most text messages get read within three minutes of arriving, and typical open rates run above 90%, compared to roughly 20% for a good email campaign. For a US small business, that makes it one of the highest-leverage channels available for time-sensitive messages: appointment reminders, flash sales, order updates, and abandoned-cart nudges. But it's also the most heavily regulated marketing channel a small business will touch, because unlike email, a text message interrupts someone's phone directly. Getting the compliance groundwork wrong doesn't just risk a few unsubscribes — it can mean per-message fines starting at $500 and carrier-level filtering that blocks every message your business sends, compliant or not. This guide covers what to actually set up, in the order that keeps you out of trouble.
Why SMS marketing isn't "email, but shorter"
Email marketing in the US is governed by CAN-SPAM, which is relatively permissive — it requires an opt-out mechanism and honest sender information, but doesn't require advance consent to send a first message. SMS marketing in the US runs under a stricter law, the Telephone Consumer Protection Act (TCPA), which generally requires prior express written consent before you send a single promotional text to a phone number. On top of the legal requirement, every US mobile carrier (Verizon, AT&T, T-Mobile) independently filters business text traffic and will silently block messages from numbers they judge to be spammy or unregistered — so even a fully consented message can fail to deliver if the sending number isn't properly set up. These two layers, legal consent and carrier registration, are both non-negotiable and neither one substitutes for the other.
Getting consent the TCPA actually requires
"Prior express written consent" has a specific meaning: the person has to take a clear, affirmative action — checking an unchecked box, texting a keyword to opt in, or signing up through a form — that discloses they're agreeing to receive recurring automated marketing texts and that message/data rates may apply. A few things that do not count as valid consent:
- A pre-checked consent checkbox on a signup form (it has to be opt-in, not opt-out).
- Collecting a phone number for order confirmations or customer service and then using it for marketing texts without separate consent.
- Buying or renting a list of phone numbers from a third party, even one marketed as "opted-in."
- Treating a single reply to a one-time text as consent to ongoing marketing messages.
Keep a timestamped record of how and when each person consented — the form they filled out, the keyword they texted, or the checkbox they checked. If a complaint or audit ever comes up, "we have no record" is the single most expensive sentence in TCPA litigation; statutory damages run $500 per violation, and $1,500 per violation if the court finds it willful, and class actions here commonly involve thousands of messages.
10DLC: registering your business to send texts at all
If you're sending marketing texts from a regular 10-digit local phone number (as opposed to a short code), US carriers require that number to go through 10DLC registration (10-Digit Long Code) before it can send application-to-person (A2P) traffic at volume. This isn't optional paperwork you can skip — unregistered numbers get aggressively throttled or blocked outright, especially by T-Mobile and AT&T. The process has two parts:
- Brand registration. Your business is registered with The Campaign Registry (TCR) using your EIN, legal business name, and address. Most SMS platforms handle this submission for you through their dashboard.
- Campaign registration. You register the specific use case for your messaging (e.g., "marketing," "mixed," "customer care") and the sample message content carriers will review. Each use case has different throughput limits — a basic low-volume campaign might cap at a few hundred messages per day per number; standard marketing campaigns, once vetted, allow much higher volume.
Registration typically takes anywhere from a few days to a couple of weeks depending on the carrier review queue and how well the brand's EIN and details match public records. Start this before you need to send your first campaign, not the week of a planned promotion.
| Sending option | Setup effort | Good for |
|---|---|---|
| 10DLC long code (registered) | Moderate — brand & campaign registration, 1–2 weeks | Most small businesses; conversational + marketing texts |
| Toll-free number (verified) | Low-moderate — toll-free verification, faster than 10DLC | Lower volume senders wanting quicker setup |
| Short code (e.g., 55555) | High — $650–$1,500/month lease plus a multi-week carrier review | High-volume senders (tens of thousands+ messages/day) |
Choosing a platform
Nearly every small business should go through a dedicated SMS marketing platform rather than attempting to manage 10DLC registration and carrier relationships directly. The platform typically handles brand/campaign registration, number provisioning, opt-out processing, and delivery reporting. When comparing options, check for: built-in TCPA-compliant opt-in forms, automatic STOP/HELP keyword handling (required by carriers, not optional), e-commerce platform integrations if you sell online, and transparent per-message pricing — costs typically run a cent or two per message plus a monthly platform fee, with carrier fees sometimes itemized separately. If you already use an email platform or CRM, check whether it has a native SMS module before adding an entirely separate tool; keeping contact data in one place avoids sync problems between email and SMS suppression lists.
What to actually send
The messages that perform best share one trait: they're short, specific, and time-relevant enough that a text is genuinely a better format than an email would be.
Transactional and service messages
Order confirmations, shipping updates, and appointment reminders. These generally fall outside strict TCPA marketing consent requirements if they're purely informational and tied to a transaction the customer initiated — but the moment a "shipping update" text includes a promotional upsell, it becomes a marketing message and needs marketing consent. Keep transactional and promotional messaging clearly separated in your platform's campaign setup.
Promotional campaigns
Flash sales, limited-time discounts, and new product announcements. These need full marketing consent and should be sent sparingly — 2–4 times per month is a reasonable ceiling for most small businesses. Sending daily promotional texts is the fastest way to drive opt-outs and carrier spam complaints simultaneously.
Abandoned-cart and reminder flows
For e-commerce businesses, a single text sent 1–2 hours after a cart abandonment reliably recovers a meaningful share of otherwise-lost sales — this is one of the highest-ROI automated flows in SMS marketing, often outperforming the equivalent email reminder in response time.
Writing texts people actually want to get
- Identify your business in the first message of any conversation. A text from an unrecognized number with no business name reads as spam and gets reported.
- Keep it under 160 characters when possible to avoid messages splitting into multiple segments (which also means multiple charges).
- Front-load the offer or reason for the text — there's no subject line to click into first.
- Always include an opt-out instruction on the first message and periodically after ("Reply STOP to unsubscribe").
- Use a clear, single call to action — one link, one offer, not a list of three things to consider.
A practical compliance checklist
| Step | Why it matters |
|---|---|
| Opt-in consent is affirmative, documented, and timestamped | This is your defense if a TCPA complaint is ever filed |
| Brand and campaign registered via 10DLC (or toll-free verified) | Unregistered numbers get filtered or blocked by carriers |
| STOP/HELP keywords handled automatically | Required by every US carrier; manual handling introduces delay and error |
| Opt-outs synced across SMS, email, and CRM | A customer who opts out of texts expects it to actually stop |
| Sending hours restricted to roughly 8am–9pm local time | TCPA guidance treats messages outside this window as higher-risk |
| Message content matches the registered campaign use case | Carriers audit content against what was registered and will throttle mismatches |
Measuring what's working
Track delivery rate, opt-out rate, and click-through rate (for links) per campaign, and watch opt-out rate closely — a sustained rate above roughly 2–3% per campaign usually signals you're sending too often or the content doesn't match what people signed up for. Compare SMS performance against your existing channels rather than in isolation; for a lot of small businesses the honest finding is that SMS works best as a amplifier for a handful of truly time-sensitive messages, not a replacement for email's broader communication volume.
Mistakes that cause the most trouble
- Texting a list collected for a different purpose. A phone number collected at checkout for order updates isn't automatically consent for marketing texts.
- Skipping 10DLC registration to save setup time. Messages get silently filtered, and you won't always get a clear error telling you why delivery rates dropped.
- No documented consent trail. Makes responding to any complaint far more expensive and risky than it needs to be.
- Sending too frequently. SMS tolerance for frequency is much lower than email's — people who'd tolerate a weekly newsletter will opt out of more than a few texts a month.
- Ignoring STOP requests promptly. Even a short delay in honoring an opt-out is a compliance risk and a fast way to generate a complaint.
Conclusion
SMS marketing pays off for US small businesses that treat the compliance groundwork as the actual product, not red tape standing between them and a campaign. Register your number, collect consent properly, document it, and keep the message volume low and relevant enough that people want to keep receiving it. Done that way, a channel with a 90%+ open rate is worth the setup time it takes to use it legally.