道歉信是指因过失或疏忽做错了事，给别人带来了麻烦或损失，发觉后要立即写信给对方赔礼道歉时写的信件。道歉是一种礼貌，道歉信要写得坦率，诚恳。
道歉信通常包括三部分内容：1、表示歉意，道歉的原由;2、出现差错的原因，提出弥补措施;3、请求原谅。语言要诚挚，解释的理由要真实。好的道歉信不仅会取得对方的谅解，还会增进彼此的感情。 写作"三步曲"：
表示歉意→说明具体原因、提出补救办法→再次致歉，希望得到理解。
英语道歉信范文：
Directions: You were unable to attend Mr. Smith's examination on International Business English Writing because you got sick that morning. Write a letter to express the reasons for not being able to attend it and apologize.
Write the letter with no less than 100 words. Do not sign your own name at end of the letter. Use "Wang Hua" instead. Do not write the address. Dear Mr. Smith,
I am indeed very sorry that I missed the examination on International Business English Writing you gave last Friday. I feel awful about it and want you to know what happened that day. I suddenly fell sick early that morning and my parents had to send me to the hospital. Please find enclosed a copy of the medical bill.
I sincerely hope you can understand my situation and accept my apology. I would appreciate your allowing me to take a make-up examination. I will come to your office during your office hour on Monday to discuss this possibility with you. Once again, I apologize for any inconvenience caused. Sincerely yours, Wang Hua
常用句式：
1、I am writing to apologize for … /I am writing to say sorry for 我写这封信是因……向你致歉。
2、I would like to give you my apology for… 对于……我向你道歉。
3、Please accept my sincere apology for…关于……请接受我真诚的道歉。
4、I am indeed very sorry for what I said/did, but believe I had no Intention to
对于我说的话/做的事，我确实感到很抱歉。但请相信，我并非故意要……
5、Please forgive me for a stupid choice of words. 请原谅我说话欠妥。
6、I feel awfully sorry about it and want you to know what happened. 为此我感到非常内疚，所以想告诉你实情。 7、Please accept my apologies for my oversight. 请原谅我的疏忽。
8、Please allow me to say sorry again.请允许我再次表示歉意。
9、I sincerely hope you can understand my situation/think in my position and accept my apologies.我真心希望你能理解我的处境/设身处地地为我考虑，并接受我的道歉。
10、Once again, I'm sorry for any inconvenience caused/you have sustained. 对于造成的不便我再次表示歉意。