Abstract: A system for establishing an instant messaging communication channel between a first account ID and a second account ID is disclosed, wherein each of the first account ID and the second account ID is registered with a same instant messaging service, the system comprising: a database for respectively associating a plurality of identifications to a plurality of account ID(s) of the instant messaging service; and a server, configured to: associate a first account ID with a first identification in the database, obtain a same first identification from a message received from a second account ID, so as to establish an instant messaging communication channel between the first account and the second account of the instant messaging service according to the same first identification.