Need to terminate a client contract? It's important to know when it's time to say goodbye.Figure out what to say in a client termination letter to ensure a professional exit and use our letter template to save time. This article will provide a detailed guide to professionally terminating a contract, including 3 contract termination sample letters and analysis. How to fill out the Sample Letter of Termination from a Case? 1. Insert the client's name at the top of the letter. 2. Providers should maintain information about the service termination in the person's record. Providers should maintain information about the service termination in the person's record.