Methods, systems, and devices for wireless communications are described. In some examples, a base station or other network entity may allocate uplink resources to UEs, or groups of UEs, that are subsequently reallocated. For example, a base station may determine a reallocation of uplink resources and issue a cancellation or preemption indication that may correspond to at least a portion of the previously-allocated resources (e.g., as allocated to particular UEs). UEs may be configured to monitor for cancellation or preemption indications, and based on received cancellation or preemption indications, UEs may determine whether or not to proceed with an uplink transmission using their previously-allocated uplink resources.