When writing a letter of retirement to an employer,

it is critical to submit the letter at least six weeks before the planned date of retirement. This will give your employer the time they need to find a replacement and do any required training needed to fulfill your responsibilities. Although an employer might be aware of your upcoming retirement, it is still considered a good idea to submit a retirement letter well in advance of the retirement date. This is considered a professional courtesy for an employer.

In the retirement letter itself, be certain to reveal the actual date of planned retirement.
Retirement letters are also a great opportunity to thank an employer for years of employment. Be certain to also thank your supervisor and coworkers for all that they have meant over the past years. Let friends know what they have meant to you.
You will also need to make certain that the transition is as trouble free as possible for the company. Promise to meet with a potential replacement, and do anything else that might be needed to ensure that the transition is smooth.

This is also a good moment to make any intentions about part time consulting services known. Many retirees continue working as consultants and contractors, so consider this as a potential avenue for post retirement income.

Many retirement letters can be quite lengthy, but the basics must still be covered.
The most crucial points are when you will retire, thanking immediate friends, and stressing that you will remain of assistance during the transition. Beyond that, a retirement letter can assume several additional forms. You can also send retirement letters to coworkers if you wish.

Think of a retirement letter as a chance to express your feelings about the company, the people you worked with, and the future.
This is one of the best opportunities that will come along to express these kinds of thoughts, especially in writing.
When you begin writing, you may find that there is more to say than you thought. The list of people that you wish to thank can easily grow quite long. Be sure to make these well deserved thanks, however, because retirement letters are the best place possible to make your well wishes known to everyone.

Evan