It is a formal letter written by a prospective candidate, as an official response to an interview call letter, in order to accept the offer. Whenever you are writing the letter make sure that your tone is formal and extremely professional. Do not try to rush in with conclusions and whenever you are accepting the offer, make sure that you keep everything concise.
Since you are writing to a senior person, you are supposed to remain extremely formal throughout the letter. Moreover, always start off by letting the other person know about the date and time of the interview call. Make them comfortable with whatever you write.
Sample of Interview Acceptance Letter
Mr. John Dane
Human Resource Manager
Adrian Maintenance Ltd.
13 Main St.
Dear Mr. Dane,
I am writing this letter in response to the interview call, dated March 12, 2012, for the post of Assistant Secretary in your company. You had asked me for a confirmation and I am glad to inform you that I will be appearing for my second interview on March 25, 2012.
It is with great pride that I am confirming the interview call, and am looking forward to having another fruitful discussion with you. I will be bringing along all relevant documentation, as per your request, so that the process can move on smoothly and efficiently. However, if you need any further information or paperwork, kindly let me know as soon as possible so that I can make the necessary arrangements.
I again thank you for presenting me with the opportunity of becoming a part of your company. I hope that I can meet your expectations.