A system and method for exchanging messages between a mobile device and a plurality of IM services. The system includes an SMS-based MIM client that runs on a mobile device and provides a plurality of user interfaces for a plurality of respective IM services. A user of the mobile device can log in to at least one of the IM services using the MIM client, and the mobile phone user can use the MIM client to exchange text messages with users logged into the at least one chosen IM service.