How To Write A Closure Letter . These can be referred to as “gratitude letters.”. Since you will be writing the termination letter on the company letterhead, the company's name and address will be already printed at the top. FREE 11+ Sample Closing Business Letter Templates in PDF MS Word from www.sampletemplates.com Include your name, account number, and any tax id numbers that. The purpose of the closing sentence. You can write the date either at the right or left top of the letter, below the printed header.