Short answer: SMS compliance means texting only people who agreed to hear from you, making it easy to stop, and sending at sensible hours. In the US, the TCPA and FCC rules set the legal baseline and CTIA's Messaging Principles set what carriers expect. Marketing texts need express written consent, and STOP must always work.
SMS compliance is the set of rules and habits that keep your text messaging legal, welcome and effective. Done right, it protects your business from fines and your numbers from carrier filters.
This guide covers TCPA basics, consent by message type, opt-outs, quiet hours and the habits that keep campaigns healthy. It also explains what changes, and what does not, when you send from your own SIM with VoidFix Gateway.
This guide is general information, not legal advice. Check the rules for your industry and every country you text with qualified counsel.
Why does SMS compliance matter?
SMS compliance decides whether your messages reach people and whether your business stays out of legal trouble. Regulators take unsolicited texting seriously, carriers filter unwanted traffic, and recipients can report a message in a tap. One careless campaign can lead to fines, blocked numbers and lasting damage to your reputation.
The good news is that compliance and results pull in the same direction. Messages people agreed to receive get read, draw fewer complaints and keep your numbers healthy.
What does the TCPA require for business texts?
In the United States, the main law is the Telephone Consumer Protection Act (47 U.S.C. 227), or TCPA. It governs how businesses contact consumers by phone and text. The FCC's rules under it sit in 47 CFR 64.1200. Three points matter most for texting:
- Consent first. Automated marketing texts need the recipient's prior express written consent.
- Revocation is easy. Under 64.1200(a)(10), people can revoke consent by any reasonable method. A reply of "stop", "quit", "end", "revoke", "opt out", "cancel" or "unsubscribe" counts.
- Damages add up per message. The statute lets recipients recover $500 per violation, and a court can triple that for willful or knowing violations.
Outside the US, local law applies. In the EU, GDPR Article 7 says you must be able to show consent was given, and withdrawing it must be as easy as giving it. The common thread is consent: people agree before you text them, and they can change their mind.
Which consent do you need for each type of message?
Carriers follow CTIA's Messaging Principles and Best Practices (May 2023). They sort business texts into three types, each with its own consent level:
| Message type | Example | Who texts first | Consent CTIA expects |
|---|---|---|---|
| Conversational | A customer asks about opening hours and you reply once | The customer | Implied consent: no extra permission needed for a relevant reply |
| Informational | Appointment reminders, welcome texts, order alerts | Either side | Express consent: the person gave their number for that purpose |
| Promotional | A sale, coupon code or offer | The business | Express written consent to receive promotional texts |
Source: CTIA Messaging Principles and Best Practices, Exhibit II (May 2023). Adding a call to action, such as a coupon code, can turn an informational text into a promotional one. Our guide to transactional versus promotional SMS explains the difference in more depth.
How do you build a solid opt-in process?
How you collect consent decides how defensible your program is. Aim for consent that is explicit, informed and documented.
- Be explicit. Use an unchecked checkbox, a keyword text-in or a clear button the person actively chooses. Never assume consent from silence or a pre-ticked box.
- Be informative. Tell people what they are signing up for, roughly how often you will text, and that message and data rates may apply.
- Be specific. Consent to order updates is not consent to promotions. Keep transactional and marketing opt-ins separate.
- Keep records. Store the timestamp, the source and the exact wording the person agreed to. If a complaint arises, this record is your defense.
A clean opt-in list also performs better. People who chose to hear from you engage more and complain less.
How should you handle opt-outs and suppression?
Every recipient must be able to opt out easily, and you must honor the request promptly. CTIA recommends standard "STOP" wording in your instructions. It also expects senders to act on normal language such as "end", "unsubscribe", "cancel" or "please opt me out".
- Recognize stop words. Process STOP, UNSUBSCRIBE and similar replies automatically.
- Confirm the opt-out. Send one confirmation that the person is unsubscribed, then go silent.
- Keep a suppression list. Hold a master list of opted-out numbers and check every send against it.
- Respect re-consent. Only resume messaging if the person explicitly opts back in.
Texting someone who asked you to stop is also the fastest way to collect complaints that get your numbers filtered.
What content and timing rules apply?
Even with perfect consent, careless content and timing erode trust and trigger filters. A few habits keep your program lawful and welcome.
- Identify yourself. Recipients should never have to guess which business a message came from.
- Respect quiet hours. FCC rules bar telephone solicitations before 8 a.m. or after 9 p.m. in the recipient's local time (64.1200(c)(1)). Some states set tighter windows, so check where your contacts live.
- Keep frequency reasonable. Over-messaging is a common reason people opt out. Text when you have something useful to say.
- Avoid prohibited content. CTIA asks senders to prevent unlawful, deceptive or fraudulent messages, and carriers restrict some categories. Know the rules for your industry.
- Repeat the opt-out. Remind recipients how to stop from time to time, especially in long-running programs.
How do you protect your sender reputation?
Carriers watch complaint rates, opt-out rates and message patterns to decide whether to trust your traffic. A compliant program produces the signals carriers reward: few complaints, clean lists and relevant content.
In practice, pace your sends, remove invalid numbers, segment so each message is relevant, and watch opt-out trends. Treat a rising opt-out rate as a reason to review frequency and content before carriers act for you.
Does sending from your own SIM change the rules?
VoidFix Gateway sends from real SIMs in Android phones. That is a person-to-person route, so A2P 10DLC registration is not part of the setup. It does not change the rules above. CTIA counts any message a business sends as Non-Consumer traffic, whatever the route. Carriers can still filter or suspend lines that send high volumes or unsolicited texts, and many consumer SIM plans limit commercial bulk use.
VoidFix gives you tools that help you follow the rules:
- Two-way messaging, so STOP replies are captured and acted on.
- Contacts and unsubscribe management, so opted-out numbers stay suppressed.
- Number Warmup, Spintax and Number Pool rotation, so no single line sends sudden, repetitive bursts.
- Integrations with GoHighLevel, Zapier, Make and a REST API, so consent records and suppression lists stay in sync with your CRM.
When your consent process is in place, our SMS pricing page shows the plans for sending from your own numbers. For specific questions, contact our team.
Frequently asked questions
Do I need written consent to send marketing texts?
In the US, yes. Automated marketing texts need prior express written consent under the TCPA rules, and CTIA expects express written consent for promotional messages. Keep a record of when and how each person agreed.
What hours can I send marketing texts?
FCC rules bar telephone solicitations before 8 a.m. or after 9 p.m. in the recipient's local time. Some states are stricter, so schedule campaigns by the recipient's time zone.
Which opt-out words do I have to honor?
The FCC treats replies of stop, quit, end, revoke, opt out, cancel and unsubscribe as valid revocation, and any other reasonable request counts too. CTIA also expects senders to act on plain language such as "please opt me out".
Does sending without A2P registration mean compliance rules don't apply?
No. Sending from your own SIM means 10DLC registration is not part of the setup, but consent, opt-out and quiet-hour rules still apply. Carriers can also filter or suspend lines that send high volumes or unsolicited texts.
Compliance keeps your texting program working
Strong SMS compliance is the foundation of a messaging program that keeps performing. Understand the TCPA basics, match consent to the message type, honor opt-outs and send content people want. That protects your business and your numbers. When you are ready, you can start your free trial with no credit card required.
