This method is used to send data representative of the location of communication terminals (T) to a call center (ECC) without using information processing means in the terminals and to send via heterogeneous communication networks (RP, RPT). This method consists, in the event of requesting the setting up of a telephone call between a terminal (T) and the call center (ECC) by means of a dedicated calling number, in sending the call center a signaling message for setting up the connection and comprising a selected call identifier and a text type message including data representative of the location of the calling terminal (T) and the selected call identifier. At the call center, the method consists in associating the signaling message received by the call center with the location data contained in the text message received by the call center if the signaling message and the text message include the same call identifier.