According to an example aspect of the present invention, there is provided a method comprising, transmitting to a Network Function, NF, service producer, by a Service Communication Proxy, SCP, a service request on behalf of an NF service consumer, wherein the service request comprises an access token, receiving, by the SCP, a service response from the NF service producer and upon receiving the service response, transmitting to the NF service consumer, by the SCP, information related to the access token.