A device may receive an outgoing message from a primary user device associated with an originating telephone number. The originating telephone number may be associated with the primary user device and one or more associated user devices. The device may identify the one or more associated user devices that are associated with the originating telephone number. The device may generate, based on the outgoing message, one or more outgoing synchronization messages corresponding to the one or more associated user devices. The one or more outgoing synchronization messages may be used to synchronize one or more outgoing messages, corresponding to the one or more associated user devices, with the outgoing message. The device may provide the one or more outgoing synchronization messages to the one or more associated user devices to synchronize the one or more outgoing messages with the outgoing message.