In recent years, Instant Messaging (IM) has become one of the most growing online communities, reaching millions of users at home and at work worldwide. As the community expands, assuming multiple identities (MID) becomes a common behaviour of the IM members. This paper reports our ongoing research on the support for MID. Our study used an online survey and face-to-face interviews to identify user needs in supporting MID in IM. The study has identified five themes including single nickname, multiple avatars,
multiple statuses, boundary control and interoperability. Reflecting on these themes, we propose a model of MID support in IM.