Acceptance letters are written to formally accept an open position offered by an organization to the employee. In fact it is always preferred to accept the offer in a written communication even after a verbal acceptance has already been made.
There are various aspects to writing an acceptance letter including the tone in which letter is to be written, the format, and the content.
The tone of the letter should be gracious and pleasing one as it will be part of the first impression the new employer has about you.
The format followed is the same as writing any other business or professional correspondence which should contain name of the person the letter is being addressed to, proper subject line at the top, date of acceptance and name and signature of the accepting party at the bottom. The letter should always be addressed to the person who had made the offer.
The content of the letter of the could be used for reiterating the facts of the offer accepted, including the designation, salary details and a brief understanding of your role and responsibility towards the organization. Since, the letter could become a permanent part of your professional file it is highly advisable to recheck and avoid spelling or grammatical mistakes.