30125: Your phone number could not be registered with US A2P 10DLC

This warning appears when you try to add a phone number to a Messaging Service that is associated with a US A2P 10DLC Sole Proprietor campaign that already has a registered sender. Sole Proprietor brands are limited to one campaign, and Sole Proprietor campaigns can use only one phone number. If you send SMS or MMS messages to recipients in the US from this phone number before it is registered to an approved campaign, that traffic is treated as unregistered and additional fees may apply.

• Your Sole Proprietor campaign already has one phone number registered.
• You tried to add a second phone number to a Messaging Service that is linked to a Sole Proprietor campaign.
• Your US messaging use case requires more than one sender, which is not supported for Sole Proprietor registration.

• Keep the currently registered phone number on the Sole Proprietor campaign if you only need one sender for US messaging.
• If you want to use a different phone number, remove the existing sender from the Messaging Service associated with the Sole Proprietor campaign, then add the replacement number and allow registration to complete before sending to US recipients.
• If you need to keep multiple phone numbers or need more scale, register a Standard or Low-Volume Standard brand and campaign, then move your Messaging Service or sender to the newly approved campaign.
• If you do not need to send messages to recipients in the US with this phone number, continue using it for supported non-US messaging traffic.

• US A2P 10DLC Overview
• Direct Sole Proprietor Registration Overview
• Transition from a Sole Proprietor to a Standard Brand