The most common reasons your refund landed at $400 instead of a larger sum

A $400 refund usually means the IRS applied money you were owed to something else first — most often back taxes, unpaid child support, or a federal student loan in default. The second most common reason is that you made a mistake on your return or the IRS found one during processing, which reduced the amount owed to you. A third possibility is that you received a partial refund because you filed jointly with a spouse who had a debt, and the IRS split the refund between you.

Less often, the $400 is actually correct and your initial estimate was simply wrong — you may have miscalculated withholding, received income you didn't account for, or claimed a credit you weren't may have access to to. The IRS processes millions of returns and catches errors constantly, so a smaller-than-expected refund is not unusual.

The key is finding out which of these happened to you, because the fix depends on the reason. If money was offset, you need to know to whom and why. If there was an error, you need to know whether it was yours or the IRS's.

Key Takeaways

  • The IRS automatically takes refund money to pay back taxes, unpaid child support, defaulted student loans, and some other federal debts before sending you anything.
  • You will receive a notice in the mail if your refund was reduced by offset; the notice names the debt and the agency collecting it.
  • Check your IRS transcript and your original return side by side to spot calculation errors that might explain the smaller amount.
  • If you filed jointly, the IRS may have offset only your spouse's portion of the refund, leaving you with a partial payment.
  • Contact the IRS at 800-829-1040 or the agency that collected the offset to dispute the debt or set up a payment plan.

How the IRS offsets refunds against federal debts

When you file your tax return, the IRS doesn't send your refund directly to your bank account or mailbox. It first checks whether you owe money to the federal government — back income taxes, unpaid child support enforced through federal channels, a defaulted federal student loan, or an overpayment of unemployment benefits. If you do, the IRS takes your refund and sends it to the agency or person you owe.

This process is called offset, and it happens automatically. You don't have to do anything to trigger it, and you can't stop it once your return is filed. The IRS will send you a notice by mail explaining what happened, which debt was collected, and how much was taken. This notice arrives separately from your refund and can take a few weeks to reach you.

If you owe back child support, the offset goes to your state's child support enforcement agency, which then forwards it to the custodial parent or the state. If you owe a defaulted federal student loan, the offset goes to the Department of Education. If you owe back taxes, the offset stays with the IRS. The timing varies — some offsets are processed within days, others take weeks.

What to look for in your IRS notice

The notice the IRS sends will tell you the type of debt, the amount offset, and the agency responsible. Read it carefully, because it also tells you how to dispute the offset if you believe it was wrong — for instance, if the debt was already paid, if it belongs to someone else, or if you have a legal claim against it.

The notice will include a phone number for the agency that collected the money. If the offset was for child support, call your state's child support enforcement office. If it was for a student loan, call the Department of Education's offset coordinator. If it was for back taxes, call the IRS. Each agency has its own dispute process, and you usually have a limited window to challenge the offset — often 60 days from the date of the notice.

Keep the notice. You will need it if you contact the agency or if you file a dispute. Do not throw it away or assume the offset was correct just because it happened.

Errors on your return or the IRS's processing

If you did not receive an offset notice and your refund is still smaller than you expected, the IRS may have found an error during processing. Common errors include claiming a dependent who doesn't meet the requirements, overstating business losses, or miscalculating the Earned Income Tax Credit. The IRS catches these during its automated review and adjusts your refund downward.

You can check what the IRS actually processed by viewing your tax transcript on IRS.gov. Log in to your account under "Get Transcript" and download the "Account Transcript" for the year in question. This shows the income, deductions, and credits the IRS recorded. Compare it line by line to the return you filed. If they don't match, the IRS made a change.

If the IRS made an error — for example, it disallowed a legitimate deduction or miscalculated a credit — you can file an amended return or contact the IRS to dispute the adjustment. If you made the error, you can file an amended return to correct it, though this may not increase your refund if the original return was already processed and the refund already sent.

Joint returns and split offsets

If you filed a joint return with a spouse and only one of you has a federal debt, the IRS will offset only that person's share of the refund. This means you receive a partial refund while your spouse's portion goes to pay their debt. You will still receive a notice explaining the offset, and it will specify whose debt was collected.

This situation often surprises couples who expected the full refund. The IRS treats each spouse's tax liability separately even on a joint return, so it can offset one person's refund without touching the other's. If you believe the offset was wrong or if your spouse disputes the debt, each of you must contact the relevant agency separately.

You may also be able to file an Injured Spouse claim if you believe you should not be held responsible for your spouse's debt. This is a separate form (Form 8379) that asks the IRS to allocate the refund based on each person's individual tax situation. The rules are strict, and not all situations may have access to, so read the instructions carefully or contact a tax professional.

Recalculating your expected refund

Before assuming something went wrong, double-check your own math. Many people estimate their refund based on a rough calculation and are surprised when the actual amount is different. Common reasons for the gap include:

  • You received a bonus, inheritance, or other income you didn't report to your employer, so your withholding was too high.
  • You claimed a credit you later found out you didn't meet the income or filing-status requirements for.
  • You had self-employment income and owed self-employment tax, which reduced your refund.
  • You received unemployment benefits, which are taxable and may have reduced your refund if you didn't have tax withheld.
  • You made a math error on the return itself — adding up deductions wrong, for example.

Use the IRS's online tax calculator or a tax software's refund estimator to recalculate based on your actual income and withholding. If the recalculated amount matches the $400 you received, there is no error — your refund was simply smaller than you thought it would be.

What to do next

If you received an offset notice, contact the agency listed on the notice to understand the debt and your options. Many agencies offer payment plans or hardship waivers if you can show you cannot pay the full amount at once. Do not ignore the notice.

If you did not receive an offset notice and believe the IRS made an error, pull your transcript and compare it to your return. If the IRS changed something, you can call 800-829-1040 to ask why. Have your return and transcript in front of you when you call. If you made the error, you can file an amended return (Form 1040-X) to correct it, though this may not result in a larger refund if the original refund was already sent.

If you filed jointly and your spouse's debt caused the offset, your spouse should contact the agency that collected the debt. If you believe you may have access to for an Injured Spouse claim, file Form 8379 with the IRS within three years of the original return's due date.

Frequently Asked Questions

Will I get the rest of my refund later?

No. Once the IRS offsets your refund to pay a debt, that money is gone — it goes to the agency or person you owe. You will not receive it later. If you believe the offset was wrong, you must dispute the debt with the agency that collected it, not the IRS.

Can I appeal an offset?

Yes, but you must contact the agency that collected the money, not the IRS. Each agency has its own appeal process. You usually have 60 days from the date of the offset notice to file a dispute. The notice will tell you how to do this.

What if the $400 is actually my spouse's refund and I got nothing?

This can happen on a joint return if your spouse had a debt and the entire refund was offset to pay it. You may be able to file Form 8379 (Injured Spouse Claim) to recover your portion. You must file this within three years of the return's due date. Read the form's instructions or consult a tax professional, as the rules are complex.

How long does it take to get an offset notice?

The IRS usually sends the notice within two to four weeks of processing your return, but it can take longer. If you received your refund but no notice, contact the IRS at 800-829-1040 to ask whether an offset was applied.

Can I prevent an offset if I know I owe money?

No. The offset happens automatically once you file your return. If you know you owe a debt, you can contact the creditor or agency before filing to set up a payment plan, which may prevent the offset, but once the return is filed, the IRS will offset if the debt is in the system.