Abstract: Known telecommunication systems utilize of a telecommunication exchange with a switching matrix coupled to a storage device for storing a message. A calling subscriber dialing a certain telephone number will hear this message, whereafter he may be put through. An advertising subscriber dialing a different telephone number, gains access to the storage device, in order to enable him to modify his message. The sometimes poor access option to said storage device may be considerably enhanced by extending the telecommunication system by a further storage device which provides a better access option and in which the new message is provisionally stored. The new message is then fed, at a convenient moment for the telecommunication system, to the storage device. Apart from this, an advertising subscriber, due to application of a table memory in the further storage device, needs to pass through a modification procedure only once, even if the message should be modified in several storage devices.