You have sent the maximum allowable daily messages for your Brand to the carrier.
Daily limits are based on your Brand Trust Score. You can check both your Trust Score and your daily Limit in the console here.
Note: That the daily limit applies to the Brand (per EIN) and is based on the total number of outbound SMS segments and MMS messages sent to T-Mobile (including Sprint and MetroPCS) across any messaging platform you have registered your Brand with.
Please refer to our documentation on T-Mobile daily message limits for long code messaging with A2P 10DLC. For more info about A2P 10DLC, refer to our US A2P 10DLC Documentation.