A2P 10DLC registration, explained for dental practices
Why your appointment reminders started failing, what the carriers are actually checking, and how long it takes.
If your practice sends appointment reminders from a normal ten-digit number, US carriers require that number to be registered under a framework called A2P 10DLC — application-to-person, ten-digit long code. Unregistered traffic is filtered, and filtering looks exactly like messages silently not arriving.
Registration has two parts. First the brand: your legal business name, your EIN, and your address, checked against public records. Then the campaign: what you intend to send, with sample messages and an explanation of how patients opt in.
The brand step is where most practices get rejected, and the reason is almost always trivial. The legal name has to match your EIN registration exactly — 'Cedar Ridge Family Dental PC', not 'Cedar Ridge Dental'. The address has to match too. A DBA that differs from the registered entity will fail.
The campaign step is where the carriers look at your actual messages. They want to see how a patient consents to receive texts, they want STOP and HELP handled, and they want your sample messages to look like what you will really send. Vague samples get rejected.
Timelines: brand vetting usually clears in two to five business days. Campaign review is slower and less predictable — one to four weeks is the honest range, and it has been at the longer end through 2026.
In the meantime you are not stuck. Toll-free numbers use a separate, faster verification path, so a practice can start sending confirmations on a toll-free number within a day or two and move to its local number once the 10DLC campaign clears.
One thing worth internalizing: this is a carrier requirement, not a vendor policy. No provider can exempt you from it, and any provider claiming otherwise is either misinformed or planning to send your reminders into a filter.