What A2P 10DLC is
Application-to-Person 10-Digit Long Code is the US carrier framework for business texting from ordinary local numbers. Businesses register who they are (the brand) and what they send (the campaign). Registered traffic gets delivered at proper throughput; unregistered traffic is throttled or filtered outright. GoHighLevel will happily show a filtered message as "sent", which is why the problem hides for weeks.
Other countries have their own rules (sender ID registration in several markets, for instance), but the principle is the same: register first, text second.
Start it on day one
Approval can take a few days or a few weeks depending on the brand's verification. We submit registration on day one of every project, before pipelines or workflows, because every outbound automation depends on it. If a client is switching to GoHighLevel from another platform, we start registration even before the contract is signed where we can.
Brand registration
The brand is the legal business. Every detail must match official records exactly: legal name as registered, EIN or company number, registered address, and a live website that clearly belongs to that business. Mismatches are the number one cause of failed verification. Sole traders use the sole-proprietor path with personal verification. We collect these details on the intake form so registration isn't waiting on someone to find a tax document.
Campaign registration
The campaign describes the messages. Approval reviewers look for four things: a clear use case (appointment reminders, customer care, marketing), a description of how people opt in, sample messages that match the use case, and opt-out language. Our sample messages are the real templates from the account, each ending with "Reply STOP to opt out". The opt-in description points to the actual form or booking page with its consent checkbox.
The website or form referenced in registration must show visible consent language for SMS. Reviewers check. So do regulators. A one-line checkbox above the submit button, unchecked by default, is the standard we use.
Common rejection reasons
- Brand name doesn't match the legal registration (trading name used instead).
- Website missing, under construction, or with no privacy policy mentioning SMS.
- Sample messages that don't match the declared use case, or lack opt-out text.
- Opt-in flow described vaguely ("customers agree") with no visible mechanism.
- Mixed use cases in one campaign: marketing blasts and appointment reminders should usually be separate.
A rejection isn't the end; it's a resubmission with the specific fix. But each round costs days, which is why getting the details right first matters.
After approval
Opt-out must be automatic: GoHighLevel handles STOP replies natively as long as the setting is on. We check delivery reports monthly for error codes that indicate filtering, keep the samples on file, and re-register the campaign if the message content changes materially. Registration is maintenance, not a one-off.
Key takeaways
- A2P 10DLC is carrier registration for business texting from standard numbers in the US. Without it, messages are filtered.
- Submit on day one of any project. Approval takes days, sometimes weeks, and nothing outbound works properly until then.
- Brand details must match the legal business registration exactly: name, EIN, address, website.
- Campaign descriptions and sample messages must show opt-in, opt-out and the real content you will send.
- After approval, keep opt-out handling automatic and monitor delivery rates monthly.