What is A2P 10DLC?
A2P stands for application-to-person. 10DLC means 10-digit long code. In the United States, carriers use A2P 10DLC registration to identify the business sending application-originated messages, the messaging use case, and how recipients consent to receive those messages.
HighLevel states that businesses using LC Phone with local U.S. numbers must register their brand and campaigns through The Campaign Registry for A2P messaging.
What is SIM-based messaging?
SIM-based messaging sends texts through a real Android device and wireless-carrier SIM. From GoHighLevel, the agency can still work through workflows and Conversations, but the outbound transport ultimately happens through the mobile device.
| Area | A2P 10DLC / LC Phone route | SIM-based route |
|---|---|---|
| Transport | Application messaging through registered local business number | Android device + carrier SIM |
| Brand/campaign registration | Required for U.S. local-number A2P traffic | Not the traditional LC Phone/TCR provisioning path |
| Consent requirement | Yes | Yes |
| STOP/opt-out responsibility | Yes | Yes |
| Carrier policies | Apply | Apply |
| Physical Android device | No | Yes |
What A2P registration is trying to accomplish
The carrier framework is designed to improve sender transparency and reduce unwanted business messaging. HighLevel's A2P guidance emphasizes sender identity, clear opt-in language, messaging purpose, and the ability for users to opt out.
What changes with SIM-based SMS?
The provisioning architecture changes. Instead of registering a local application-messaging campaign through LC Phone, your agency operates a carrier-connected mobile number on a physical Android device. That can simplify one part of setup and change the cost model, but it introduces device and carrier management.
What does not change
- You should only message people when you have a lawful basis and appropriate consent.
- Opt-out requests must be honored.
- You remain responsible for TCPA and other applicable rules.
- Your wireless carrier can impose acceptable-use and fair-use restrictions.
- High complaint or opt-out rates can still create deliverability or account problems.
How ASG frames the difference
Agency SMS Gateway describes its architecture as SIM-based transport that does not use the traditional LC Phone/Twilio A2P 10DLC provisioning path. We deliberately do not describe it as “compliance-free SMS” or a method for sending unsolicited messages.