Some techniques and apparatuses described herein permit a user equipment (UE) to signal a capability corresponding to a number of active beams (e.g., active uplink beams) to a base station so that the UE may be appropriately configured, and so that the UE may communicate with the base station accordingly. Furthermore, some techniques and apparatuses described herein permit a UE and/or a base station to apply one or more rules and/or conditions to assist with ensuring that a UE capability, corresponding to a number of active beams (e.g., active uplink beams), is not violated, or to prevent the UE from communicating on a beam that is invalid due to a violated UE capability. Furthermore, some techniques and apparatuses described herein permit a UE and a base station to perform a beam management procedure upon beam activation to ensure that a beam is of sufficient quality for communications.