Techniques to reconfigure messaging clients during contact information changes are described. In one embodiment, an apparatus may comprise a messaging component operative to receive a contact phone number update at a messaging client on the client device from a messaging system, the contact phone number update associated with a contact with the messaging client, the contact phone number update comprising a previous phone number and an updated phone number; determine an existing message thread for the messaging client identified based on the previous phone number; and send a user message to the contact via the messaging system using the updated phone number as a destination address; and a user interface component operative to display a contact phone number change notification in the existing message thread; and receive the user message for the contact. Other embodiments are described and claimed.