We've got you covered with 25 customer apology letter templates so you can swiftly say "I'm sorry" and start delivering a solution. Dear Customer, I apologize for the lateness of this order.It is not the way we like to treat our valued customers. Find out what goes into writing effective, heartfelt customer apology emails with these best practices and free templates. Why am I receiving a backorder letter? You are receiving a backorder letter because the item you have requested is currently out of stock. We believe in transparency and honesty - that includes when we've messed up. Begin your apology letter with a sincere statement apologizing for your action or mistake. I trust this letter finds you well. I wish to take this opportunity to express my sincere regret for the way I left things the last time we met.