A method for delivering a short message service (SMS) message to an interworking wireless local area network user equipment (UE) begins by registering the UE with an Internet Protocol short message gateway (IP-SM-GW). A capability report is sent from the UE to the IP-SM-GW, the capability report including the capabilities of the UE. A SMS message is transmitted from a short message service center (SMSC) to the IP-SM-GW. The capabilities of the UE are evaluated at the IP-SM-GW to determine whether the UE can receive the SMS message, and the SMS message is delivered to the UE via the IP-SM-GW if the UE has the capabilities to receive the SMS message.