In the first paragraph of your letter, explain why you are writing the IRS. Mention the date of their notice.Learn how to write a letter to the IRS with our comprehensive guide and sample. Includes ChatGPT prompt. What Tone Should I Use in the Letter? Use a respectful and professional tone, regardless of the nature of the issue or your sentiments about it. We have provided sample letters that you can use to request waivers of several different types of IRS penalties. Fill out the "Reply to FTB" form included with your notice.