Form 843, Claim for Refund and Request for Abatement, is how you ask the IRS to refund or cancel certain taxes, penalties, additions to tax, interest and fees. As of October 2026, its most common uses are asking for a penalty to be removed for reasonable cause and claiming back excess Social Security or Medicare tax an employer won't fix, and you generally have 3 years from filing or 2 years from paying, whichever is later.
It's not a catch-all refund form. The IRS's own instructions start with a list of what you can't use it for, and getting that wrong is the quickest way to wait months for nothing. Here's how to tell if Form 843 is the right one.
What you can use Form 843 for
- A refund or abatement of a penalty or addition to tax for reasonable cause or another reason the law allows.
- Abatement of a penalty or addition to tax caused by erroneous written advice from the IRS.
- Abatement of interest caused by IRS error or delay under section 6404(e).
- A refund of excess Social Security, Medicare or RRTA tax withheld by one employer, if the employer won't adjust it.
- A refund of Social Security or Medicare tax withheld in error, if the employer won't adjust it.
- Abatement or refund of a Trust Fund Recovery Penalty.
- A refund or abatement of other taxes, apart from income, estate or gift tax.
The reasonable-cause request also covers the section 6676 penalty for an erroneous refund claim, which the instructions say is assessed at 20% of the amount found to be excessive.
When you can't use Form 843
| What you want | Use instead |
|---|---|
| A refund of income tax or Additional Medicare Tax | An amended return, such as Form 1040-X |
| To change amounts on your Form 1040 | Form 1040-X |
| An employer refund or abatement of FICA tax, RRTA tax or income tax withholding | The correction form for the return you filed, such as Form 941-X for Form 941 |
| To amend an income or employment tax return | That return's own amended version |
| Abatement of income, estate or gift tax | Not available on Form 843 |
The employer row is the one that surprises people. An employer can't use Form 843 for its own FICA or withholding corrections, but an employee can use it to reclaim excess tax that employer withheld and won't put right.
The time limit
Generally, you must file a claim for a credit or refund within 3 years from the date you filed the original return, or 2 years from the date you paid the tax, whichever is later. Miss it and you may no longer be entitled to the refund. You also file a separate Form 843 for each tax period or fee year and each type of tax or fee, with a few exceptions for interest claims.
How to fill in Form 843
- Tick the box at the top that gives your reason for filing.
- Enter your name, taxpayer identification number and address.
- Lines 1 to 4: the tax period, the amount and the date of payment if you've already paid it.
- Line 5: tick the type of return or fee the claim relates to.
- Line 6: for an assessed penalty, enter the Internal Revenue Code section, which is usually printed on the IRS notice.
- Line 7: tick the reason box (a, b or c, or d if none of those apply).
- Line 8: explain in detail, show your calculation and attach your evidence.
- Sign it. On a joint return both spouses sign, a corporation's form is signed by an authorized officer with their title, and an estate or trust's by the fiduciary.
If you're replying to an IRS notice, mail the form to the return address on the notice, not a general address.
Penalty relief from written IRS advice
The IRS can abate a penalty caused by wrong written advice from an IRS officer or employee, but only if all three conditions are met: you reasonably relied on the advice, it answered a specific written request from you or your authorized representative, and the penalty didn't come from you giving the IRS inadequate or inaccurate information. You tick box b on line 7 and attach your written request and the advice.
Excess Social Security withheld by an employer
If one employer took too much Social Security or Medicare tax and won't refund it, attach a statement from that employer if you can. It should show what the employer has repaid you and any credit or refund it has claimed. If you can't get one, write your own statement with the same details to the best of your knowledge, explain why the employer's isn't available, and attach your Form W-2.
Using a representative
Your authorized representative can file Form 843 for you, but the original or a copy of Form 2848 must be attached. A legal representative of someone who has died attaches proof of authority and also files Form 1310.
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The verdict
Use Form 843 for penalties, interest and the narrow employee tax refunds it was built for, and use an amended return for everything about income tax. If you're asking for a penalty to be removed, the explanation on line 8 is the whole case, so make it specific, dated and backed by documents. And diarise the 3 year and 2 year limits the day the bill arrives.
Frequently asked questions
What is Form 843 used for?
To claim a refund or request an abatement of certain taxes, penalties, additions to tax, interest and fees, such as penalty relief for reasonable cause.
Can I use Form 843 for an income tax refund?
No. The instructions say not to use it for a refund of income tax or Additional Medicare Tax. Use an amended return such as Form 1040-X.
What is the deadline for Form 843?
Generally 3 years from the date you filed the original return or 2 years from the date you paid the tax, whichever is later.
Where do I send Form 843?
If you're responding to an IRS notice, mail it to the return address the notice came from.
Can an employer use Form 843 to fix payroll tax?
No. Employers use the correction form for the return they filed, such as Form 941-X, for FICA, RRTA or withholding.
Do I need a separate Form 843 for each year?
Generally yes: one for each tax period or fee year and each type of tax or fee, with some exceptions for interest claims.
