A method for processing communications in a telephony network, the method comprising: processing at least one SMS message in SMS processing equipment in the telephony network, wherein a first telephony identifier is associated with a group of users including at least a first user and a second user, wherein a second telephony identifier is associated with the second user, and wherein each of the first and second telephony identifiers is useable as a destination address in an SMS message sent to the second user, wherein said processing at least one SMS message in the SMS processing equipment comprises: receiving a mobile-originating SMS message from the second user; and transmitting an outgoing SMS message to a third user, the outgoing SMS message including an originating address comprising the first telephony identifier; and performing identity management, in relation to the use of the first and second telephony identifiers for the second user, during said processing of the at least one SMS message at the SMS processing equipment, wherein said performing identity management comprises: accessing group messaging indicator data indicative of an association between the first user and the second user; and selecting the first telephony identifier on the basis of the group messaging indicator data, wherein the group messaging indicator data comprise a third telephony identifier, the third telephony identifier being an identifier for the third user, and wherein said selecting comprises deriving the third telephony identifier from a destination address of the mobile-originating SMS message and, in response to the group messaging indicator data being indicative of an association between the first telephony identifier and the third telephony identifier, selecting the first telephony identifier. processing at least one SMS message in SMS processing equipment in the telephony network, wherein a first telephony identifier is associated with a group of users including at least a first user and a second user, wherein a second telephony identifier is associated with the second user, and wherein each of the first and second telephony identifiers is useable as a destination address in an SMS message sent to the second user, wherein said processing at least one SMS message in the SMS processing equipment comprises: receiving a mobile-originating SMS message from the second user; and transmitting an outgoing SMS message to a third user, the outgoing SMS message including an originating address comprising the first telephony identifier; and receiving a mobile-originating SMS message from the second user; and transmitting an outgoing SMS message to a third user, the outgoing SMS message including an originating address comprising the first telephony identifier; and performing identity management, in relation to the use of the first and second telephony identifiers for the second user, during said processing of the at least one SMS message at the SMS processing equipment, wherein said performing identity management comprises: accessing group messaging indicator data indicative of an association between the first user and the second user; and selecting the first telephony identifier on the basis of the group messaging indicator data, accessing group messaging indicator data indicative of an association between the first user and the second user; and selecting the first telephony identifier on the basis of the group messaging indicator data, wherein the group messaging indicator data comprise a third telephony identifier, the third telephony identifier being an identifier for the third user, and wherein said selecting comprises deriving the third telephony identifier from a destination address of the mobile-originating SMS message and, in response to the group messaging indicator data being indicative of an association between the first telephony identifier and the third telephony identifier, selecting the first telephony identifier.