This document describes techniques and devices for communication of dual connectivity (DC) capability by user equipment (110) to a base station (120) and a core network (150) using signaling of a modification of the DC capability of the UE (110) at the physical layer (306) or the media access control layer (308) to reduce the latency of communicating the modification of the DC capability as compared to using Radio Resource Control layer (322) signaling. Signaling a modification of DC capability at the physical layer (306) or media access control layer (308) enables the UE (110) to more quickly respond to issues detected by the UE (110), such as thermal management or in-device coexistence interference, that may be mitigated by discontinuing DC communications.