Rocket Lawyer's free Response to IRS Notice form provides a step-by-step interview process that makes it easy to write a letter to the IRS. In this article, we will provide you with a detailed guide on the steps involved in writing a letter to the IRS.You may file a Form 140X. If you choose this option, you must amend your Arizona return within 90 days of the final determination of the IRS. Use Form 843 to claim a refund or request an abatement of certain taxes, penalties, additions to tax, interest, and fees. Learn how to change your business name with the IRS. If you amend your federal return for any year, you must also file an Arizona Form 140X for that year. You generally have 30 days to respond to an IRS notice, so there's no reason to ignore it. Always check which tax year the notice relates to. Use Form 8822, Change of Address or Form 8822B, Change of Address or Responsible Party Business Tax return.