Embodiments of the present invention relate to a messaging system for managing communications resources and are particularly suitable for providing a means for subscribers of a telecommunications network to continue participating in a communications service that would otherwise be ended due to the calling party having a low or zero balance. Embodiments of the invention are generally applicable to users of a mobile network.Embodiments of the invention provide a messaging system for use by the telecommunications network to transmit a message to a remote party, where the remote party is identified by means of a telephone calling identifier associated with a call setup request for a telecommunications session received from a user of the telecommunications network. The messaging system comprises a storage system for storing data providing a predetermined definition of message content to be sent to the remote party. In response to trigger event such as determining that the account balance available for said user participating in the requested communications session is below a predetermined threshold, the messaging system is arranged to initiate the transmission of a message to said remote party. The transmitted message contains message content that is defined at least in part by said definition of message content and can comprise a "call me message". This thereby ensures that a "call me" message reaches the remote party.