A method for preventing subscriber identifier leakage from a telecommunications network includes receiving, by a security edge protection proxy (SEPP), an authentication response message authorizing a subscriber in a visitor network, wherein the authentication response message includes a home subscriber identifier used to identify the subscriber within a home network. The method further includes replacing, by the SEPP, the home subscriber identifier in the authentication response message with a visitor subscriber identifier. The method further includes forwarding, by the SEPP, the authentication response message with the visitor subscriber identifier to a visitor network.