The first thing to do if you receive a letter from the IRS is to find out if it's legitimate. Use Form 8822-B to notify the Internal.Learn how to write a letter to the IRS with our comprehensive guide and sample. Includes ChatGPT prompt. Learn how to change your business name with the IRS. You can use Form 8822 to notify the Internal. Revenue Service if you changed your home mailing address. Send a typewritten letter to the IRS office that sent the notice. Use the format in the sample letter below. Access IRS forms, instructions and publications in electronic and print media.