Methods, apparatuses, and computer program products for submitting and/or delivering a SMS between user equipment without MSISDN are provided. One method includes storing the SIP-URI and IMSI for a device sending a SMS. Themethod may further include receiving a SMS from the sending device. In an embodiment, the TP-DA field of the MO-SMS is filled with value(s) that indicates the recipient UE is addressed without MSISDN, the R-URI is set to PSI, and the "to header" is set to the receiving device's SIP URI. The method may include retrieving the receiving device's SIP URI from the "to header," and querying the receiving device's HSS for the IMSI and routing information of the receiving device. The method may then include delivering the SMS to the receiving device directly or delivering the SMS to the receiving device via the SMSC.