Under the new A2P 10DLC service for sending messages via 10-digit long code numbers in the United States, there are changes to how message sending throughput is allocated. A2P 10DLC message throughput in the US will now be determined based on your Brand type, Campaign type (use case), and Trust Score (for Standard Brands). This guide gives an overview of these changes, and how throughput is allocated.
T-Mobile will also impose daily message limits toward their subscribers. This is separate from message sending throughput. See T-Mobile daily message limits for long code messaging with A2P 10DLC for details.