This document describes techniques and systems that enable a base-station-initiated grant revoke. The techniques and systems allow a base station to generate and send a grant-revocation message (GRM) to a user equipment (UE) to revoke a scheduled uplink (UL) or downlink (DL) grant from the base station. The base station can transmit the GRM to the UE using a variety of techniques. For example, based on a trigger event, the base station may assign a UE identifier, such as a specific radio network temporary identifier (RNTI), to the UE and transmit the GRM to the UE using a revoke-physical-downlink-control-channel (R PDCCH) transmission that is associated with the UE identifier. These techniques allow the base station to revoke a scheduled UL or DL grant, which can enable the UE to quickly address timing-critical resource allocation issues and mitigate the effects of adverse operating conditions.