Guides
A2P 10DLC Compliance for AI SMS Follow-Up: What Revenue Teams Need to Know
A practical guide to A2P messaging registration, 10DLC compliance, and TCPA consent requirements for teams using AI agents to send automated follow-up texts.
Guides
A practical guide to A2P messaging registration, 10DLC compliance, and TCPA consent requirements for teams using AI agents to send automated follow-up texts.
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If your team uses AI agents to send follow-up text messages — appointment confirmations, quote reminders, re-engagement nudges, or missed-call texts — every one of those messages is classified as Application-to-PersonA2P messagingApplication-to-person SMS — the category for business messages sent from a software platform like Thoughtly. Subject to carrier registration and content rules. (A2P) messaging under U.S. carrierCarrierA telecommunications provider that routes phone calls and SMS over its network. Twilio, Telnyx, and Bandwidth are the three most common in the AI voice space. rules. That classification triggers a set of registration, consent, and content requirements that did not exist five years ago and that have only gotten stricter since 2024.
This guide explains the three regulatory layers that govern business SMS in the United States — the TCPATCPAUS federal law governing telemarketing calls and SMS. Thoughtly enforces consent capture, time-of-day windows, and DNC scrubbing automatically. and FCC rules, the CTIA Messaging Principles, and the 10DLC10DLC10-Digit Long Code — US carrier-mandated registration for A2P SMS. Without it, your business texts get filtered or blocked. registration system — and walks through the practical steps a revenue or operations team needs to take before an AI agent sends its first text.
AI-powered lead conversion platforms like Thoughtly send SMS automatically — after a missed call, as part of a multi-channel cadence, or as a booking confirmation. The volume and automation that make these workflows effective are also what put them squarely under the A2P messaging framework.
Non-compliance carries three categories of risk:
Business SMS in the U.S. is governed by three overlapping layers. Each adds its own requirements.
The Telephone Consumer Protection Act (47 U.S.C. § 227) applies to text messages the same way it applies to calls. Key requirements for AI-generated SMS:
The CTIA (the wireless industry trade association) publishes Messaging Principles and Best Practices that carriers use as the baseline for their filtering and compliance programs. Key points:
10DLC (10-Digit Long Code) is the carrier-mandated system for registering business SMS sent from standard local phone numbers. It is administered through The Campaign Registry (TCR), a centralized database that T-Mobile, AT&T, and Verizon use to verify senders and campaigns.
Registration has two steps:
As of February 2025, unregistered A2P 10DLC traffic is fully blocked by major U.S. carriers. There are no exceptions. If your campaign is not registered and approved, messages from your 10DLC numbers will not be delivered.
Use this checklist before enabling automated SMS on any AI agent workflowWorkflowAn automated, multi-step process — usually triggered by an event (form fill, new lead) and orchestrating one or more voice / SMS / email actions..
| Step | Action | Why it matters |
|---|---|---|
| 1. Register your brand | Complete TCR brand registration through your messaging provider (Twilio, Telnyx, Bandwidth, etc.). Provide EIN, legal entity name, and website. | Required for any A2P 10DLC traffic. Without this, messages are blocked. |
| 2. Register each campaign | Create a campaign for each distinct use case. Describe the message purpose, provide 2–3 sample messages, and link your opt-in flow and privacy policy. | Carriers review campaigns individually. Mismatched content triggers filtering. |
| 3. Build one-to-one consent | Ensure your web forms, landing pages, and lead-capture flows collect consent that names your company specifically. One checkbox per seller, per the FCC's January 2025 rule. | Blanket multi-seller consent is no longer valid for marketing texts under the amended TCPA. |
| 4. Document opt-in evidence | Store timestamps, IP addresses, form URLs, and the exact consent language the lead agreed to. Keep records for at least five years. | Consent records are your primary defense in any TCPA dispute. |
| 5. Implement opt-out handling | Honor STOP, UNSUBSCRIBE, CANCEL, END, and QUIT immediately. Send a confirmation reply. Propagate the opt-out across all channels (voice, SMS, email). | Required by TCPA, CTIA guidelines, and carrier policies. Failure to honor opt-outs is the most common enforcement trigger. |
| 6. Identify the sender | Include your business name in every SMS. The first message in a thread should also include opt-out instructions and a message frequency disclosure. | CTIA and carrier requirements. Reduces spam reports. |
| 7. Match content to campaign | Only send messages that match the registered campaign use case. Do not repurpose appointment-reminder campaigns for promotional content. | Content mismatch is the top cause of campaign suspension and carrier filtering. |
| 8. Monitor throughput and filtering | Track delivery rates, carrier error codes, and opt-out rates. Investigate any sudden drops in deliverability. | Early detection prevents large-scale message loss and helps you respond to carrier audits. |
| 9. Respect quiet hours | Follow state-specific calling and texting time restrictions. As a baseline, avoid texting before 8 AM or after 9 PM in the recipient's local time zone. | Several states impose their own quiet-hour rules; violating them adds to TCPA exposure. |
| 10. Scrub against DNC lists | Check every outbound list against the National Do Not Call Registry and your internal suppression list before sending. |
Thoughtly is not a compliance certification body and does not replace legal counsel. It is a platform with built-in features that help revenue teams implement compliant SMS workflows alongside their voice and email agent programs.
Some teams enable AI SMS follow-up before completing 10DLC registration, assuming their messaging provider handles it automatically. The provider provisions the number, but you must register the brand and campaign yourself (or through the provider's registration portal). Without approval, messages are silently dropped.
Campaigns described as "customer updates" or "notifications" are being rejected at higher rates, especially by T-Mobile. Be specific: "AI agent sends follow-up texts to insurance leads who requested a quote via our website, including appointment confirmations and coverage option summaries" is far more likely to be approved than a generic label.
Under the FCC's one-to-one consent rule (effective January 27, 2025), a single checkbox that covers multiple sellers or partners is not valid consent for marketing texts. If you acquire leads from comparison-shopping sites or lead aggregators, verify that the consent flow names your company specifically and that the lead actively selected your brand.
A lead who replies STOP to a text has revoked SMS consent. Continuing to text them — even with non-promotional content — violates TCPA and carrier rules. Worse, some teams accidentally continue contacting the lead via voice after an SMS opt-out, which may violate the spirit of the opt-out even if the legal analysis for voice is technically separate. Cross-channel suppression eliminates this risk.
A campaign registered for appointment reminders cannot also include "Ask about our spring discount" in the message body. Carriers audit message content and suspend campaigns that deviate from the registered use case. If you need both transactional and promotional messaging, register separate campaigns.
Yes. The 10DLC requirement applies to all A2P SMS sent from U.S. local numbers, regardless of volume. Even a single automated text from an AI agent qualifies as A2P traffic and must be registered.
10DLC numbers are standard 10-digit local numbers (e.g., 415-555-0198). They require TCR registration but offer local presence and are the most common choice for AI lead-follow-up. Toll-free numbers (800, 888, etc.) have their own verification process through carriers, not TCR. Short codes (5–6 digit numbers) are pre-approved for high-volume messaging but cost significantly more and require a longer approval process. Each type has different throughput limits, pricing, and use-case suitability.
As of mid-2026, campaign reviews typically take 10 to 15 business days, though timelines vary by carrier and messaging provider. Plan for this lead time before launching any new SMS agent workflow. Brand registration is usually faster — often approved within a few business days.
The one-to-one consent rule specifically amends the definition of prior express written consent, which applies to telemarketing robocalls and robotexts. Purely informational texts — such as an appointment confirmation the consumer directly requested — may fall under the lower "prior express consent" standard, which does not require a written agreement. However, the line between informational and promotional is fact-specific. If your AI follow-up text includes any sales or marketing language, treat it as requiring prior express written consent with one-to-one specificity.
Campaign suspensions halt all SMS delivery on the associated numbers. Common causes include content that deviates from the registered use case, high spam-report rates, or missing opt-in documentation during a carrier audit. To resolve a suspension, update your campaign registration, fix the content mismatch, provide opt-in evidence, and resubmit through your messaging provider. Resolution timelines vary.
This article is informational and does not constitute legal advice. Consult qualified legal counsel for compliance decisions specific to your organization.
| Texting a number on the DNC list with marketing content is a TCPA violation. |