SMS Compliance Guide

Business SMS in the United States is regulated by the Telephone Consumer Protection Act (TCPA) and enforced at the carrier level through the A2P 10DLC registration system. Every business that sends text messages to customers through an application, including booking confirmations, appointment reminders, and follow-up messages, is classified as an A2P (Application-to-Person) sender and must be registered.

• Protects Your DeliverabilityRegistered messages reach customers. Unregistered messages are silently blocked.
• Required by LawTCPA violations carry fines of $500 to $1,500 per message sent without proper consent.
• One-Time SetupBrand and campaign registration is done once, not per message or per recipient.
• We Handle It For YouBlack Tiger Digital manages the full registration process for our clients.

Every business that sends appointment reminders, booking confirmations, follow-up messages, or any automated text through Twilio must complete brand registration and campaign registration before sending. There are no exceptions for small businesses.

A2P stands for Application-to-Person. 10DLC stands for 10-Digit Long Code, the standard 10-digit phone numbers used for business SMS (as opposed to shortcodes). The A2P 10DLC system is a framework created by U.S. carriers (AT&T, T-Mobile, Verizon, and others) that requires businesses to register their brand identity and message use cases before sending business SMS at scale.

Why It Was Created

Before A2P 10DLC, spam and fraud text messages were rampant because anyone could send texts from a standard 10-digit number without any verification. The registration system was created to:

• Verify Sender IdentityCarriers know who is sending messages and can hold businesses accountable.
• Reduce SpamUnregistered senders are filtered. Registered senders get preferential delivery.
• Enforce TCPACreates a traceable record linking message types to consenting recipients.
• Improve ThroughputRegistered numbers get higher sending limits and better delivery rates.

The Bottom Line: If your phone number is not registered under the A2P 10DLC system, your text messages will be filtered or silently blocked by major U.S. carriers, and neither you nor your customer will know the message never arrived.

Brand registration is the first step. It establishes your business identity with The Campaign Registry (TCR), the third-party organization that manages A2P 10DLC registration on behalf of U.S. carriers.

What You Will Need

• Legal Business NameExactly as it appears on your business registration or EIN documents.
• EIN / Tax IDYour Employer Identification Number. Required for all U.S. business registrations.
• Business WebsiteAn active website that matches your business name and clearly shows your services.
• Business EmailA business email address at your domain, not a free consumer inbox.
• Business AddressA verifiable physical address, not a P.O. Box.
• Business TypeYour industry vertical (healthcare, retail, professional services, and so on).

Vetting: Some brand registrations require “Standard Vetting,” a paid identity verification step that unlocks higher daily message limits. Black Tiger Digital will advise you on whether this applies to your account.

See our full step-by-step guide: Twilio Brand Registration.

After your brand is registered, each distinct type of messaging you send must be registered as a Campaign. A campaign describes the use case, the specific purpose for which you are sending messages. This is how carriers confirm that your messages match what you said you would send.

Common Use Cases for Our Clients

• Appointment RemindersReminders sent to customers before upcoming appointments. The most common use case for our clients.
• Booking ConfirmationsAutomated confirmation texts sent immediately after a booking is made.
• Customer CareTwo-way conversational messages with existing customers about their appointments or service.
• Review RequestsPost-service messages asking customers to leave a review, sent to consenting customers only.

What Each Campaign Registration Requires

• 1Use Case DescriptionA clear description of exactly what types of messages you will send and why.
• 2Sample MessagesTwo to three example messages that accurately represent what you will send. These must match the actual messages.
• 3Opt-In Method DocumentationProof of how you collect consent: a form, a checkbox at booking, or a documented verbal agreement.
• 4Opt-Out LanguageConfirmation that your messages include STOP instructions and that opt-outs are honored immediately.

See our full step-by-step guide: Twilio Campaign Registration.

The Telephone Consumer Protection Act (TCPA) is federal law. It requires businesses to obtain prior express written consent before sending marketing or automated text messages to any customer. Violations carry fines of $500 per message for negligent violations and $1,500 per message for willful violations, with no cap on class action damages.

What Valid Consent Looks Like

• Online Booking Form CheckboxAn unchecked checkbox at booking: “I agree to receive text message reminders and updates from [Business Name]. Reply STOP to opt out.” This is the gold standard and what we use by default.
• Paper Intake FormA physical form signed by the customer that includes explicit SMS consent language, not buried in fine print.
• Keyword Opt-InCustomer texts a keyword (for example, “JOIN”) to your number after being clearly informed of what they are signing up for.

What Does NOT Count as Consent: Simply having a customer’s phone number, a previous business relationship, or a verbal agreement that was not documented does not meet TCPA consent requirements.

Opt-Out Rules: Non-Negotiable

• STOP must always work. When a customer replies STOP, UNSUBSCRIBE, CANCEL, END, or QUIT, they must be removed from all messaging immediately and automatically. No exceptions.
• Confirm the opt-out. Send one final confirmation message (for example, “You have been unsubscribed. You will receive no further messages.”) and then send nothing more.
• HELP must respond. When a customer replies HELP, your system must respond with your business name, a brief description, and instructions for opting out.

Beyond registration, the content of your messages must meet carrier standards. Messages that violate these rules will be filtered regardless of registration status.

Example of a Compliant Appointment Reminder

Our Default Setup: Our booking system is configured with compliant message templates out of the box. Business name, opt-out instructions, and accurate content are included automatically.