Find out what goes into writing effective, heartfelt customer apology emails with these best practices and free templates. Our free customer apology letter templates and comprehensive guide make it easy to craft an effective customer apology.Here's what you should say: "We sincerely apologize for this inconvenience. Making a Sorry for Out of Stock Item Letter online is simple. Just answer a few questions, and Rocket Lawyer will build your document for you. Don't know how to write an apology letter to customer? Get 4 email templates you can send out to customers when their order is delayed due to production issues. This letter of apology guides students to explain what they did, how that made others feel, and what they should have done instead. Example: "We truly regret any inconvenience this has caused you. It was our mistake and we take full responsibility for it.