Why a Legal SMS Marketing List Is Required
A legal SMS (text message) marketing list is the foundation of every successful texting program. If the list is built improperly, good messages, timing and offers will not make up for it. An illegally built list exposes you to fines of $500 to $1,500 per text under the TCPA (the federal Telephone Consumer Protection Act), class action lawsuits, carrier (phone company) blocks and platform bans.
It can be tempting to take a shortcut, such as buying a list of 50,000 phone numbers for a few hundred dollars, copying numbers from websites, or importing your email list and texting it. All of these approaches are illegal, and the penalties are severe enough to shut down a small business.
Building a legal list does not have to be slow. Using the strategies in this guide, businesses routinely build lists of hundreds or thousands of subscribers within their first few months.
SMS Opt-In Best Practices
Before anyone gets a text
- Ask in writingThe form or sheet says plainly that they agree to receive texts from you.
- Keep the recordNote the date and where each person signed up.
- Send at reasonable hoursQuiet-hours scheduling keeps texts out of the night.
- Honor STOPA STOP reply is handled automatically.
What Qualifies as Valid Consent
Under the TCPA and the rules of the FCC (Federal Communications Commission), valid SMS consent (opt-in) requires:
- Clear disclosure: The consumer must know they are agreeing to receive text messages
- Specific identification: Your business name must be included in the consent language
- Voluntary agreement: Consent can't be a condition of purchase or service
- Written form: Electronic consent (web form, text keyword) counts as "written" consent under the federal E-SIGN Act
Consent Language That Works
Your opt-in language should be direct and specific. The examples below meet the requirements:
Web form checkbox (unchecked by default):
"I agree to receive promotional text messages from [Business Name] at the number provided. Message frequency varies. Msg & data rates may apply. Reply STOP to cancel."
Text-to-join keyword:
When someone texts your keyword, send this automatic reply: "Thanks for joining [Business Name] texts. You'll receive up to 4 msgs/month with deals & updates. Msg & data rates apply. Reply STOP to cancel. Reply HELP for help."
For a complete overview, read how to text without breaking the law.
12 Proven Strategies to Build Your SMS List Fast
1. Website Pop-Up with Incentive
Offer a first-purchase discount in exchange for a phone number. "Get 15% off your first order. Enter your phone number for your exclusive code." A well-timed pop-up (after 15 seconds, or as a visitor starts to leave) turns 3 to 8% of visitors into subscribers.
2. Checkout Opt-In
Add an SMS opt-in checkbox to your checkout page. "Text me order updates and exclusive deals from [Business Name]." Checkout opt-ins have sign-up rates of 20 to 30%, because the customer already trusts you with their payment information.
3. Text-to-Join Keywords
A keyword is a word people text to your number to join your list. Promote it on signs, packaging and social media: "Text DEALS to [Number] for exclusive offers." Keywords work well because the subscriber has to take action, which shows they are interested.
4. In-Store Signage
Point-of-sale signs, table tents, window decals and register toppers all work. "Join our VIP text list. Text JOIN to [Number] for 10% off today." In-store signs typically add 10 to 30 subscribers per week at each location.
5. Social Media Promotion
Post about your text list regularly. "Our text subscribers got early access to last week's sale, and it sold out before we even emailed about it. Don't miss out next time: text VIP to [Number]." The fear of missing out encourages people to sign up.
6. Email Cross-Promotion
Ask your email subscribers to join your text list. "Want faster updates? Our text subscribers hear about deals hours before everyone else. Join here: [Link]." Typically, 5 to 10% of email subscribers who receive this invitation join.
7. Contest and Giveaway Entry
"Text WIN to [Number] for a chance to win a $100 gift card. One winner chosen Friday." Contests can add hundreds of subscribers in a few days. Make sure your contest rules include SMS consent language.
8. Loyalty Program Sign-Up
Connect your text list to your loyalty program. "Sign up for rewards and get text updates on your points, birthday rewards, and member-only deals." Loyalty members are your most valuable texting audience, because they already buy from you regularly.
9. Event Collection
At trade shows, conferences, community events, and pop-up shops, collect phone numbers with a tablet signup form. Include clear consent language on the form. In-person collection has sign-up rates of 40 to 60%.
10. QR Codes
Place QR codes (square barcodes that a phone camera can scan) on packaging, receipts, business cards and print ads, linked to an SMS opt-in page. QR code use has grown 300% since 2020, and customers are comfortable scanning them.
11. WiFi Opt-In
If you offer free WiFi (restaurants, cafes, waiting rooms), require a phone number to connect and include SMS consent. Your list then grows with every customer who uses your WiFi.
12. Referral Incentive
"Share this link with a friend. When they join our text list, you both get $5 off." Subscribers who join through a referral tend to be higher quality, because an existing customer recommended you.
What Not to Do When Building Your SMS List
- Never buy phone number lists. Purchased lists have no valid consent for your business.
- Never import your email list and start texting. Email consent is not SMS consent. You need separate, explicit opt-in for texts.
- Never pre-check the SMS consent box. Consent must be affirmative: the subscriber must actively check the box or type the keyword.
- Never add people from business card exchanges. Getting someone's card at a networking event doesn't mean they consented to marketing texts.
- Never use a shared or generic consent. Written consent must authorize the business that sends the texts, so consent collected by one business cannot be passed to another.
Maintaining Your SMS List
Building the list is the first step. Maintaining it keeps you compliant and keeps your messages effective:
- Clean your list regularly: Remove invalid numbers, landlines and long-inactive subscribers
- Process opt-outs promptly: Use a platform that automatically handles STOP requests
- Group subscribers by engagement: Subscribers who have not opened a text in 6 months may need a message inviting them back, or removal
- Back up your consent records: If challenged, you need proof of consent for every number on your list
Learn more about SMS consent requirements in our TCPA compliance guide.
Start Building Your List the Right Way
A legal SMS marketing list of 500 engaged subscribers will always produce better results than an illegally purchased list of 50,000. Subscribers who agreed to hear from you open your texts, respond to your offers and stay on your list for months or years. Contacts who never agreed produce complaints, carrier blocks and legal liability.
CampaignCNX+ gives you the tools to build and manage your SMS marketing list, including built-in consent tracking, automatic opt-out processing and compliance monitoring. Start with 100 free SMS and build your subscriber list correctly from the beginning. You get 100 free SMS to start, your number is $5 a month, and we file the carrier approval for you. That review usually takes about 3 business days for a toll-free number.
Read more about how CampaignCNX+ helps with building a list a small business can actually text.
