Method for updating a table of correspondence between a logical address associated with a user unit (STB*) in a communication network and a unique identification number associated with said user unit, this user unit belonging to a group of user units managed by a management centre, wherein said user unit comprises means for processing data, said data processing means being associated with said logical address, and wherein said user unit further comprises a security module associated with said unique identification number, said method comprising a step of exchanging messages between said management centre and at least said specific user unit (STB*) of said group by means of said communication network, these messages being forwarded to the specific user unit (STB*) using the logical address (AD*) of said user unit in said network, characterized in that it comprises the following steps: - search in said table of correspondence for the logical address (AD*) of the user unit in said communication network by using the unique identification number (UA*) corresponding to the specific user unit (STB*); - sending messages to the user unit (STB*) having said unique identification number (UA*) by using the logical address (AD*) corresponding to said communication network; - waiting for a return message from said specific user unit (STB*) having the concerned unique identification number (UA*); - in case a return message is not received, sending a request by the management centre to all or a part of the user units belonging to said group, said request containing at least said unique identification number (UA*) of said specific user unit for which the table of correspondence must be updated, and a command requesting sending a return message to the management centre; - detection of a return message from a user unit (STB*) whose unique identification number (UA*) corresponds to said identifier contained in the request; - determining the logical address (AD*) in said network, used by the user unit (STB*) having emitted the return message; - verification of the logical address by establishing a communication between the management centre and the user unit (STB*) and authentication of the specific user unit by the management centre, - storing in the table of correspondence of the management centre said logical address (AD*) of the user unit in said network, in connection with said unique identification number (UA*) of the user unit (STB*) having emitted the return messages. - search in said table of correspondence for the logical address (AD*) of the user unit in said communication network by using the unique identification number (UA*) corresponding to the specific user unit (STB*); - sending messages to the user unit (STB*) having said unique identification number (UA*) by using the logical address (AD*) corresponding to said communication network; - waiting for a return message from said specific user unit (STB*) having the concerned unique identification number (UA*); - in case a return message is not received, sending a request by the management centre to all or a part of the user units belonging to said group, said request containing at least said unique identification number (UA*) of said specific user unit for which the table of correspondence must be updated, and a command requesting sending a return message to the management centre; - detection of a return message from a user unit (STB*) whose unique identification number (UA*) corresponds to said identifier contained in the request; - determining the logical address (AD*) in said network, used by the user unit (STB*) having emitted the return message; - verification of the logical address by establishing a communication between the management centre and the user unit (STB*) and authentication of the specific user unit by the management centre, - storing in the table of correspondence of the management centre said logical address (AD*) of the user unit in said network, in connection with said unique identification number (UA*) of the user unit (STB*) having emitted the return messages.