Wireless communications systems and methods related to an uplink transmission cancellation mechanism that determines processing time for UEs configured with mixed processing capabilities are described. Specifically, methods and systems are provided for a UE to determine which processing capability to rely on to determine the minimum processing time for cancellation. For example, when a UE is configured with a faster processing capability and a slower processing capability, the UE may be configured to always rely on the faster, or the slower processing capability. Alternatively, the UE may be configured to consider factors such as the uplink channel type, uplink channel priority, the cause of the cancellation, the priority of uplink grant, or any combination thereof, to determine whether to rely on the faster or the slower capability to obtain the minimum processing time for cancellation.