The embodiments herein relate to a method performed by a PGW (108) for handling a UEs (101) access to an EPC service via a non-3GPP access network (103). During a request for connecting the UE (101) to the non-3GPP access network (103), the PGW (108) receives identity information which indicates an identity of an AAA node (710) from a non-3GPP access gateway (705). The PGW (108) selects the AAA node (710) which was indicated in the received identity information. The PGW (108) transmits, to the selected AAA node (710), a request message for the UE (101). The request message is a request for authorization of the UE (101) to access the EPC service via the non-3GPP access network (103).