SMS marketing is sending promotional and automated text messages to people who agreed to receive them, such as a welcome offer, an abandoned cart reminder or a back in stock alert. In the US it runs on express written consent and registered sender numbers. In the EU, prior consent is the default rule.
This guide is part of the marketing automation hub. The short version: get consent capture and sender registration right before the first send, start with a welcome flow, abandoned cart reminders and order updates, and choose between SMS marketing platforms on their all-in cost per message segment, not their headline rate.
What counts as SMS marketing, and what is a transactional text?
SMS marketing covers every text whose purpose is to sell or promote, such as offers, product launches and cart reminders. A transactional text is a message the customer needs to complete something they started, such as an order confirmation or a shipping update. The line matters because US and EU consent rules are stricter for marketing.
SMS is a plain text message. MMS is a multimedia message that can carry an image or a GIF, and it costs more per send.
In the US, business texts go out from one of three number types. A 10DLC number is a registered 10-digit long code. A toll-free number uses an 8XX prefix. A short code is a five or six digit number leased for high volume programs.
What consent does US law require for SMS marketing in 2026?
US SMS marketing requires prior express written consent before you send marketing texts with an automated system, under the Telephone Consumer Protection Act and the CTIA guidelines carriers enforce. As of October 2026 the FCC one-to-one consent rule is gone, and the consumer opt-out rules have applied since April 2025.
The Telephone Consumer Protection Act (TCPA) is the US federal law that restricts automated calls and texts. It lets people sue for $500 per violation, and a court can triple that for willful or knowing violations, according to the statute text, 47 U.S.C. 227. Prior express written consent is a signed agreement, electronic signatures included, that authorizes one seller to send marketing texts to one phone number and states that signing is not a condition of purchase (47 CFR 64.1200(f)(9)). FCC rules bar telephone solicitations before 8 a.m. or after 9 p.m. in the recipient's local time (47 CFR 64.1200), and state laws can be stricter.
Where the 2023 one-to-one consent rule stands as of October 2026:
- Confirmed by the court. The Eleventh Circuit vacated the rule in Insurance Marketing Coalition v. FCC on January 24, 2025, holding that the TCPA "requires only 'prior express consent'" and nothing more, as Goodwin summarized in 2025.
- Reported by law firms. The FCC then issued a final rule in 2025 that formally removed the one-to-one requirement from its rules.
- Still in force. Prior express written consent for marketing texts did not change.
Since April 11, 2025, a reply such as stop, quit, end, revoke, opt out, cancel or unsubscribe counts as a valid revocation, and you must honor it within 10 business days, as Kelley Drye reported in 2025. The separate "revoke all" requirement, where an opt-out from one type of message stops all your robotexts, is waived until January 31, 2027 by FCC Order DA 26-12 of January 6, 2026.
The CTIA Messaging Principles and Best Practices (May 2023 version) add carrier expectations: disclose the program, your identity, fees and terms at opt-in, confirm the message frequency and how to opt out, and act on plain language opt-outs.
Do you need 10DLC registration to send marketing texts?
Yes, if you send from a standard 10-digit US phone number. A2P 10DLC is the carrier standard that verifies business texting over 10-digit long codes, and both the brand and each campaign must be registered through The Campaign Registry before carriers accept the traffic. Toll-free numbers and short codes follow their own approval routes.
Twilio's A2P 10DLC documentation describes it as the standard US carriers use to make sure long code traffic is "verified and consensual". Twilio blocks messages from 10DLC numbers not tied to an approved campaign.
Twilio's 10DLC fee overview lists, as of October 2026, a one-time brand fee of $4.50 for sole proprietor and low volume brands or $46 for a standard brand, a $15 campaign vetting fee, and monthly campaign fees from $1.50 to $10 depending on the use case. Daily capacity is about 3,000 segments for a sole proprietor brand and about 6,000 for a low volume standard brand.
- Register the brand. Enter the exact legal business name as registered with your EIN, plus the tax ID and website, as Twilio's registration guide asks.
- Describe the campaign. Pick the use case, add two to five sample messages that include your brand name and describe how people opt in.
- Show the opt-in. Link to the signup form, your terms and a privacy policy that says you do not share mobile numbers, so the vetting team can check them.
- Attach your numbers. Link the 10DLC numbers to the approved campaign in your messaging provider.
- Test before you scale. Text phones on several carriers and confirm that STOP and HELP replies work.
Can you send SMS marketing to customers in the EU?
Yes, but EU law starts from prior consent. The ePrivacy Directive treats SMS as electronic mail, and its Article 13 requires the recipient's prior consent for direct marketing, with a narrow exception for existing customers. The consent itself has to meet the GDPR standard, and each member state's national law sets the details.
Recital 40 of the ePrivacy Directive names "e-mails, including SMS messages" among the unsolicited communications it covers. Article 13(2) is the existing customer exception, often called the soft opt-in. It applies only when:
- you collected the phone number yourself in the context of a sale,
- you promote your own similar products or services,
- the customer could object easily and free of charge when you collected the number,
- and every message offers the same easy way to object.
Consent under the GDPR must be freely given, specific, informed and unambiguous, and you must be able to show that a person consented. In practice: a separate, unticked SMS checkbox, a record of when and where each number opted in, and an opt-out in every message. Because ePrivacy is a directive, member states wrote their own versions, so the soft opt-in differs by country.
Which SMS marketing automations should you set up first?
Start with SMS marketing automations that react to something the customer just did: a welcome message after opt-in, an abandoned cart reminder, order and shipping updates, and a win-back message for lapsed buyers. Timely flows read as useful rather than as one more promotion.
| Flow | Trigger | Example message | Watch out for |
|---|---|---|---|
| Welcome | Number confirmed opt-in | "BrandName: Thanks for joining. Your 10% code is HELLO10. Up to 4 msgs/mo. Reply HELP for help, STOP to opt out." | Send the confirmation details CTIA expects in the first message |
| Abandoned cart | Checkout started, no order within a set delay | "BrandName: Your cart is saved. Finish your order here: [link] Reply STOP to opt out." | Exit the flow as soon as the order comes in |
| Order and shipping updates | Order placed, shipped, delivered | "BrandName: Order 1234 has shipped. Track it: [link]" | Keep promotions out of messages people asked for as service updates |
| Win-back | No order for a set period | "BrandName: It has been a while. Here is free shipping on your next order: [link] Reply STOP to opt out." | Check that the consent on file is still valid before you send |
Keep each message under 160 standard characters with the brand name first. Coordinate with your email automation flows so a customer does not get the same cart reminder by email and text within minutes. Send the email first and use SMS as a follow-up for people who did not act.
Measure each flow on revenue per message and opt-out rate per send, tag every link with UTM parameters that name the flow, and compare against a holdout group that gets no texts. The guide to attribution models explains how to credit SMS without counting the same order twice, and the same test discipline from conversion rate optimization applies to message copy and timing.
How much does SMS marketing cost per message?
SMS marketing cost is the price per segment, plus carrier fees, plus number and registration fees. A segment is the billing unit of a text: up to 160 standard characters, or 70 characters when the message contains an emoji or another special character.
Twilio's character limit guide explains the math. Standard GSM-7 text fits 160 characters in one segment and 153 per segment once a message is split. One emoji or one curly quote switches the whole message to UCS-2 encoding, which fits 70 characters in one segment and 67 per segment after that.
Hypothetical worked example. A store sends one campaign to 10,000 subscribers through Twilio from a registered 10DLC number, using Twilio's US prices as of October 2026: $0.0083 per SMS segment plus a carrier fee per outbound segment of $0.0035 (AT&T), $0.0045 (T-Mobile) or $0.005 (Verizon).
- A 130 character message in plain text is one segment: 10,000 segments cost $83 in base fees plus $35 to $50 in carrier fees, so $118 to $133.
- The same 130 characters with one emoji become two UCS-2 segments: 20,000 segments, so $236 to $266.
- On top come Twilio's 10DLC fees ($46 brand plus $15 vetting once, then up to $10 a month) and a long code number at $1.15 a month.
The decision rule: count the segments of your real messages, then compare platforms on all-in cost per 1,000 segments, never on the headline price per text.
How do you choose between SMS marketing platforms?
Choose between SMS marketing platforms on four points: the cost logic per segment, whether triggers can use your store and email data, how the tool handles consent records and quiet hours, and how it reports revenue. An SMS marketing platform is software that collects opt-ins, stores consent records and sends campaign and automated texts from registered numbers.
| Platform | Published pricing | Cost logic | Carrier fees | Fits teams that |
|---|---|---|---|---|
| Klaviyo | Rates shown in the account | Rate per message times recipients times segments, by channel, country and number type | Bundled into the rate | Already run email in Klaviyo and want one profile per customer |
| Postscript | Yes: Starter $0 a month ($49 minimum spend), Growth $100, Professional $500 | Per message rate from $0.009 down to $0.007 per SMS as the plan fee rises | Added on top, average US SMS fee listed at $0.0033 | Want a dedicated SMS tool for an online store |
| Attentive | No, quote only | Usage based: message volume, list size, channels and AI add-ons | Part of the quote | Need a quoted, multi channel package |
| Twilio | Yes, per segment | $0.0083 per SMS segment plus number and 10DLC fees | Passed through per carrier | Have developers who build their own flows |
Sources: Klaviyo's help center calls its rate "the all-in cost", Postscript's pricing page lists plans and carrier fees, and Attentive's pricing page offers quotes only.
Beyond price, check in a demo or trial:
- Consent records. Can you export when, where and with which disclosure each number opted in?
- Quiet hours. Does the tool hold sends based on the recipient's time zone, not your store's?
- Opt-out sync. Does a STOP reply update the customer profile in your email and CRM tools?
- Revenue reporting. Can you set the attribution window and export message level data?
Common mistakes with SMS marketing
Most SMS marketing problems come from consent, cost and timing rather than from copy. The mistakes below either break US or EU consent rules, raise the cost per send without anyone noticing, or reach people at hours that trigger opt-outs.
- Treating a purchase as consent. A phone number collected at checkout is not consent to marketing texts in the US. Add a separate, clearly worded SMS opt-in.
- Paying for segments you did not plan. Emojis, curly quotes and long links can double the cost of a send. Preview the segment count of every message before it goes out.
- Sending on store time. A 7 p.m. send from California lands at 10 p.m. on the East Coast. Schedule by the recipient's time zone.
- Accepting only the exact keyword STOP. Replies like "unsubscribe" or "please opt me out" count as opt-outs. Make sure your platform catches them and confirms the opt-out.
