Understanding Your Letter 4800C

What this letter is about

We’re proposing a change to your tax return.

What you need to do

  • Review your tax return for the tax year in question.
  • Review the "Changes to Your Return" section of the letter to decide if you agree or disagree with our proposed changes.
  • If you don't agree with the changes, reply to us. Make sure to include supporting documentation.

You can find a list of supporting items in the letter we sent.

Complete and return the Response Form within 30 days from the date of the letter.

  • For the fastest case resolution, reply using the Documentation Upload Tool:
    • complete your letter (signed and dated)
    • scan or take a photo of your letter showing if you agree or disagree
    • complete the upload form
    • submit your response

Reply to IRS

  • You can also reply:
    • Fax your information to the fax number in the letter using either a fax machine or an online fax service. Protect yourself when sending digital data by understanding the fax service’s privacy and security policies, or
    • Mail using the envelope enclosed with the letter.

You may want to

  • Review this notice with your tax preparer.
  • Contact the Taxpayer Advocate Service (TAS) if you're experiencing an economic hardship or need help in resolving problems. You can reach TAS at 877-777-4778 or TTY/TTD 800-829-4059.

What if you don't respond

We’ll send you a notice requesting additional documents or an explanation of adjustments we made to your tax, withholding and credits.

Frequently Asked Questions

Why is my return being reviewed?

We select some returns to determine if income, expenses, and credits are being reported accurately. This doesn't mean you made an error or were dishonest.

What will happen after I provide my response?

We'll contact you within 180 days if we have questions. If not, no action is required. It takes about 9 weeks to review your response and make any changes.

What if I didn't file the tax return?

Someone else may have filed it for you without your consent. Send us a completed and signed Form 14039, Identity Theft AffidavitPDF. You may want to read our identity theft resources page while we review your Form 14039.

Helpful Information

See our page to find answers to other frequently asked questions.