What to do if the IRS sent you less than you expected

If the IRS issued a refund that is smaller than what you calculated on your return, you have the right to dispute it. The IRS makes mistakes—they misread entries, miss deductions, or explore credits incorrectly. Your first step is to compare what you reported on your return against the IRS notice you received. The IRS will send you a letter (usually a CP12 or similar notice) explaining the change they made. That letter is your starting point, because it tells you exactly what the IRS did and why.

You do not need to hire a tax professional to challenge a refund amount, though you can. The process is straightforward if you have your original return, your supporting documents, and the IRS notice in front of you. Most disputes are resolved through the mail, and the timeline depends on whether you respond quickly and whether the IRS needs to request more information from you.

Key Takeaways

  • The IRS sends a notice explaining any changes to your refund; read this notice first because it tells you what they changed and gives you a important date to respond.
  • You respond by sending a letter to the address on the notice, explaining why the IRS made an error and including copies (never originals) of documents that support your position.
  • Keep your response focused on the specific item in dispute—do not rewrite your entire return or introduce new issues the IRS did not raise.
  • The IRS typically takes 30 to 90 days to review your response, though complex disputes can take longer.
  • If you disagree with the IRS decision after they respond, you can request an appeals conference or file a claim for refund in Tax Court.

Understanding the IRS notice you received

The IRS sends a formal notice whenever they change your refund amount. Common notices include CP12 (changes to your return), CP2000 (income the IRS matched to third-party records like W-2s or 1099s), and various adjustment notices. The notice will show the original amount you reported, the amount the IRS is now reporting, and the difference. It will also list the specific line items or credits the IRS changed.

Read the notice carefully. It will include a important date—usually 30 days from the date of the notice—to respond if you disagree. This important date matters. If you miss it, the IRS can finalize the change without hearing from you, though you still have other options later (like filing a claim for refund). The notice also includes the address where you send your response and sometimes a phone number if you have questions about what the notice says.

If the notice is unclear or you cannot find the specific reason for the change, call the IRS at the number on the notice. Have your return and the notice in front of you. The IRS phone lines are often busy, but persistence usually gets you through within a few calls.

Gathering documents that support your position

Before you write your response, collect every document related to the item in dispute. If the IRS reduced a deduction, you need receipts, invoices, or bank statements showing you spent that money. If they denied a credit, you need proof you met the requirements—birth certificates for dependents, mortgage statements for the home office deduction, tuition bills for education credits. If they added income you did not report, you need documentation showing you already reported it elsewhere or that the income was not actually yours.

Make copies of everything. Never send original documents to the IRS. They do not return them, and you may need them later if the dispute goes to appeals or court. Organize your copies in the order they appear in your response letter, and number them if there are many. A clear, organized package makes it easier for the IRS reviewer to understand your position.

If you cannot find a document—say, a receipt from years ago—write a brief explanation of what the document was, when you had it, and why you no longer have it. The IRS understands that old records get lost. A credible explanation, combined with other supporting evidence (like a credit card statement showing the charge), can be enough.

Writing your response to the IRS

Your response is a letter, not a form. Address it to the IRS office listed on the notice. Start by stating your name, Social Security number, the tax year in question, and the notice number. Then explain, in plain language, why you believe the IRS made an error. Be specific: do not say "I disagree with the deduction reduction." Instead, say "I reported $4,200 in home office expenses on Schedule C, line 30. The IRS notice shows $0. I am enclosing receipts for internet, utilities, and equipment that support this deduction."

Keep your letter focused on the one or two items the notice raised. Do not use this as an opportunity to rewrite your entire return or introduce new deductions the IRS did not question. That creates confusion and delays. Stick to the dispute at hand.

At the end of your letter, list the documents you are enclosing. For example: "Enclosed: (1) Copy of my 2023 Form 1040, (2) Copy of Schedule C, (3) Electric bills for January–December 2023, (4) Internet service invoices for 2023." This makes it clear what the IRS reviewer should expect to find in your package.

Mail your response to the address on the notice, not to the IRS main office. Use certified mail with return receipt so you have proof the IRS received it. Keep a copy for your records.

What happens after you send your response

The IRS will acknowledge receipt of your response, usually within two to four weeks. They will then assign a reviewer to examine your documents and your explanation. This review typically takes 30 to 90 days, depending on the complexity of the issue and the IRS workload. During this time, do not send additional letters or documents unless the IRS specifically asks for them. Extra mail can confuse the file and slow things down.

The IRS will send you a final notice once the review is complete. This notice will either agree with you (and issue the refund difference), partially agree (and adjust the amount), or disagree and uphold their original position. If they agree, the refund will be issued within four to six weeks of the notice date.

If the IRS disagrees with your response, the notice will explain their reasoning. At that point, you have two main options: request an appeals conference, or file a claim for refund in Tax Court.

Appeals and next steps if the IRS disagrees

If you still disagree after the IRS responds to your letter, you can request an appeals conference. This is an informal meeting with an IRS appeals officer who was not involved in the original decision. You can attend in person, by phone, or by mail. The appeals officer will review your documents and listen to your argument. This step is free and does not require a lawyer.

To request an appeals conference, send a letter to the IRS office that issued the final notice. State that you want to appeal and briefly explain why you believe the IRS decision was wrong. Include a copy of the final notice. The IRS will send you information about how to schedule the conference.

If the appeals officer also disagrees, or if you want to skip the appeals process, you can file a claim for refund in the U.S. Tax Court. This is a more formal legal process and usually requires a tax professional. You have a time limit—generally three years from the date you filed your original return—to file a claim. Tax Court handles disputes over refund amounts and can order the IRS to pay you if the court agrees you are right.

When to consider hiring a tax professional

You can handle a straightforward refund dispute on your own if the issue is straightforward—for example, the IRS denied a deduction you clearly documented, or they added income that appears on a form you already reported. A letter with supporting documents is often enough.

Consider hiring a tax professional (a CPA, enrolled agent, or tax attorney) if the dispute involves complex tax law, multiple issues, or large dollar amounts. A professional can also represent you at an appeals conference or in Tax Court, which saves you time and may improve your chances. Professionals charge by the hour or by the project. Get a quote before you hire, and ask whether they think your case is strong enough to pursue.

If you cannot afford a professional, the Taxpayer Advocate Service (TAS) is a free IRS resource that can help you navigate disputes. TAS is independent from the regular IRS and can intervene if you are having trouble getting a response or if you believe the IRS is treating you unfairly. You can reach TAS through your local IRS office or by calling 1-877-777-4778.

Frequently Asked Questions

How long do I have to respond to an IRS notice about my refund?

You have 30 days from the date on the notice to respond. If you miss this important date, the IRS can finalize the change, but you still have other options—you can request an appeals conference or file a claim for refund later. Responding within the important date is easier and faster, so do not ignore the notice.

Can I call the IRS instead of sending a letter?

You can call to ask questions about the notice or to clarify what the IRS changed, but a formal dispute must be in writing. The IRS needs a written record of your position and your supporting documents. A phone call alone will not resolve the dispute.

What if I find new documents after I send my response?

If you discover additional documents that support your position, send them to the same address with a brief cover letter explaining what they are and why they are relevant. Do this promptly, before the IRS completes their review. Do not send documents after the IRS has issued their final decision—that requires a new formal process.

Will disputing my refund amount trigger an audit of other parts of my return?

No. A dispute over a specific refund amount is limited to that issue. The IRS will not use your response as a reason to audit other deductions or income on the same return unless they already had reason to question those items.

How much does it cost to dispute a refund amount?

There is no fee to dispute a refund amount with the IRS. The appeals process is also free. You only pay if you hire a tax professional to help you, and costs vary depending on the complexity of your case and the professional's hourly rate.