The disclosure pertains to allowance of a sidelink communication operation. An a aspect is direct to an apparatus configured to determine, based on a radio resource control, RRC, state of a first user equipment and a transmission timing synchronization state of the first user equipment, UE, for a sidelink transmission of the first UE to a second UE, information indicating whether or not a sidelink communication operation of the first UE is allowed in a coverage area of a base station of a mobile communications network. The apparatus is further configured to initiate provision of the information to the first UE. Another apparatus aspect is directed to an apparatus configured to obtain information indicating whether or not a sidelink communication operation of a first UE is allowed in a coverage area of a base station of a mobile communications network, the information being determined based on an RRC state of the first UE and a transmission timing synchronization state of the first UE for a sidelink transmission of the first UE to a second UE. The apparatus is further configured to control the first UE according to the information. Further aspects of the disclosure pertain to a base station, a UE, methods, computer programs, computer readable storage media and a system.