How to Fill Out IRS Form 843: Line-by-Line Instructions and Deadlines

IRS Form 843, Claim for Refund and Request for Abatement, is a one-page paper form you use to ask the IRS to cancel certain penalties, abate interest caused by IRS error or delay, or refund specific overpayments such as excess Social Security or Medicare tax withheld by an employer.¹ To fill out IRS Form 843 correctly, you complete one form per tax period and per type of tax, check the single box on Line 7 that matches your reason for filing, write a factual explanation on Line 8, attach supporting documents, sign, and mail it to the address that matches your situation. There is no electronic filing option.

Confirm Form 843 Is the Right Form First

Form 843 covers a narrow set of requests. Using it for the wrong purpose gets the claim rejected outright, not just delayed.

Use it to request:

Abatement or refund of a failure-to-file, failure-to-pay, or other penalty when you have reasonable cause, plus specific penalties under Sections 6672 (trust fund recovery), 6695A (incorrect appraisals), and dyed-fuel misuse rules.²
Abatement of interest attributable to an unreasonable IRS error or delay under Section 6404(e).³
An employee refund of Social Security or Medicare tax withheld above the annual wage base ($184,500 for 2026) when the employer won’t correct it.⁴⁵
A refund of overpaid estate tax (Form 706) or gift tax (Form 709).
Refunds tied to branded prescription drug fees, annual fees on health insurance providers, and Form 8300 penalties.⁶

Do not use Form 843 to reduce income tax, estate tax, or gift tax itself; to claim a refund of income tax or Additional Medicare Tax; to amend an income or employment tax return; or to recover installment agreement fees, offer-in-compromise fees, or lien fees. Amend an individual return on Form 1040-X, a corporate return on Form 1120-X, and correct employer FICA or withholding on Form 941-X. Excise refunds go on Form 8849, fuel credits on Form 4136.⁷

Check First Time Abate Before Filing

If you’re seeking penalty relief, call the number on your IRS notice before filling out anything. The First Time Abate administrative waiver removes a failure-to-file, failure-to-pay, or failure-to-deposit penalty for taxpayers with a clean compliance record in the three prior tax years, and it doesn’t require you to prove reasonable cause.⁸ If the agent approves it on the call, the penalty comes off immediately with no paperwork. If not, you can still file Form 843.⁹

The waiver applies to the earliest qualifying year only and does not cover accuracy-related or estimated tax penalties. When you file Form 843 for reasonable cause, the IRS will check First Time Abate eligibility anyway and apply it if you qualify.

Filling Out the Form Line by Line

Download the current revision from IRS.gov. File a separate Form 843 for each tax period and each type of tax or fee.⁶

Header

Enter your name, address, and taxpayer identification number. Individuals use their Social Security number; businesses use an EIN. On a joint claim, include both names and SSNs. A daytime phone number is optional but useful.

Line 1: Tax Period

Enter the beginning and ending dates of the period covered. For a calendar-year income tax matter that’s January 1 through December 31 of the year involved. For quarterly employment taxes, use the quarter’s dates. For a branded prescription drug fee refund, enter the fee year.⁵

Line 2: Amount

Enter the exact dollar amount you want refunded or abated. For a penalty, use the amount shown on the IRS notice. For excess FICA, calculate the overage from your W-2.

Line 3: Dates of Payment

If you already paid the amount and want it refunded, list each payment date. Attach additional sheets if there were multiple payments.

Line 4: Type of Tax or Fee

Check the box for the underlying tax: employment tax, estate tax, gift tax, excise tax, or penalty/fee. If your claim involves interest or a penalty, check the box for the tax that produced the charge, not a generic penalty box.

Line 5: Type of Return

Check the box for the return connected to your claim: Form 940, 941, 943, 944, 945, 720, 1040, or CT-1. This routes the form to the right IRS branch.⁵

Line 6: IRC Section

If you’re requesting abatement of a specific penalty, enter the Internal Revenue Code section that authorized it. The section number appears on the IRS notice near the penalty amount.

Line 7: Reason for Filing

Check the one checkbox that best fits. The most commonly used options:

Abatement or refund of a penalty or addition to tax due to reasonable cause or other reason allowed under the law
Abatement or refund of interest due to IRS error or delay under section 6404(e)(1)
Refund to employee of excess social security, Medicare, or RRTA tax withheld by any one employer
Abatement or refund under section 6404(f) of a penalty or addition to tax attributable to erroneous written advice by the IRS

If none apply, check “Other” and describe the situation in the space provided.⁶

Line 8: Writing the Explanation

Line 8 is where the claim is actually decided. Keep it factual and chronological. Include specific dates: when you got the notice, when you paid, when the IRS error occurred. Reference each attached document by name. Skip legal argument and emotional appeals.

Reasonable Cause

For a reasonable-cause penalty request, show that you exercised ordinary care and prudence but still couldn’t comply. Circumstances that commonly qualify:

Fire, natural disaster, or civil disturbance that destroyed records or blocked access to your tax professional
Death, serious illness, or unavoidable absence involving you or an immediate family member
Inability to obtain necessary records despite diligent effort
IRS system issues that blocked timely electronic filing or payment¹⁰

Not knowing about a deadline, an honest mistake on a return, or general lack of funds without more will not clear the bar. Blaming a tax preparer will not either; the IRS holds you responsible for meeting deadlines even when you delegate.¹⁰

Interest Abatement for IRS Error

For Section 6404(e) interest abatement, identify the specific IRS action and the period over which interest accrued because of it. The IRS distinguishes between ministerial acts (routine procedural steps with no judgment involved, such as transferring a case after approval or issuing a notice of deficiency) and managerial acts (administrative decisions like assigning personnel). Both can qualify when the delay was unreasonable. Broader policy decisions, such as how the IRS organizes return processing or timing of computer system upgrades, do not.¹¹

Supporting Documents

Attach copies, never originals. Depending on the claim:

The IRS notice or letter that assessed the penalty or interest
Medical records, discharge papers, or a death certificate for illness or death
Insurance claims, fire department reports, or FEMA declarations for disaster claims
Your W-2 showing excess withholding for an employee FICA refund
A statement from your employer confirming they have not already refunded or claimed the excess
Your original written request for IRS advice and the erroneous written response, for a Section 6404(f) claim⁵

Signing and Mailing

Sign and date the form. Your signature certifies that everything on it is true. A paid preparer who helped you signs separately and enters a preparer tax identification number.

Mailing address depends on the reason you’re filing:

Responding to an IRS notice: send it to the return address on that notice.
Estate or gift tax refund: Internal Revenue Service, Attn: E&G, Stop 824G, 7940 Kentucky Drive, Florence, KY 41042-2915.
Form 8300 penalty: Internal Revenue Service, Rosa Parks Federal Building, P.O. Box 32621, Detroit, MI 48232.
Net interest rate of zero: the service center where you filed your most recent return.
Anything else, including penalty abatement: the service center where you would file a current-year return for the type of tax involved. The instructions for that return give the address.⁷

Send it USPS Certified Mail with a return receipt. The counter-stamped acceptance date serves as proof of timely filing under 26 U.S.C. § 7502. Self-service kiosks and Click-N-Ship labels only prove when you bought postage, not when USPS accepted the item.

Deadlines

Refund claims on Form 843 follow the general refund statute: file within three years from the date you filed the original return, or within two years from the date you paid the tax, whichever expires later. If you never filed a return, the window is two years from the date of payment.¹² Miss the deadline and the IRS has no authority to pay the refund, even if the underlying claim is valid.

Abatement requests, where you’re asking the IRS to cancel a charge rather than refund a payment, aren’t subject to the same strict deadline. File promptly anyway. Interest continues to accrue on an underlying balance while the IRS reviews the claim; filing Form 843 does not pause the clock.¹³

After You File

Processing runs from a few weeks for simple penalty requests to several months for interest abatement claims that require the IRS to reconstruct its own timeline. The IRS may write to request more documentation. When a decision is made, you receive a notice stating whether the claim was allowed in full, allowed in part, or denied. Approved refunds arrive as a check or direct deposit.

If the claim is denied, you generally have 30 days from the date on the rejection letter to request a conference with the IRS Independent Office of Appeals. The letter itself will state the exact deadline and explain how to request the appeal.¹⁴ Appeals officers are independent from the examiner who denied the claim. If Appeals also denies, or if the claim was for a refund, you may be able to sue in federal district court or the U.S. Court of Federal Claims; the two-year window for filing suit generally begins when the IRS mails its final disallowance notice.

If the IRS never responds, the Taxpayer Advocate Service can push it along. You qualify for TAS help when the IRS misses normal processing time by more than 30 days, sends repeated “we need more time” letters without action, or misses a committed response date. File Form 911 with your local Taxpayer Advocate office.¹⁵ TAS can break a processing logjam but cannot overturn a legal determination the IRS has already made.

1
Internal Revenue Service. About Form 843, Claim for Refund and Request for Abatement
2
Office of the Law Revision Counsel. 26 U.S. Code 6651 – Failure To File Tax Return or To Pay Tax
3
Office of the Law Revision Counsel. 26 U.S. Code 6404 – Abatements
4
Social Security Administration. Contribution and Benefit Base
5
Internal Revenue Service. Instructions for Form 843 – Claim for Refund and Request for Abatement
6
Internal Revenue Service. Form 843 – Claim for Refund and Request for Abatement
7
Internal Revenue Service. Instructions for Form 843 – Claim for Refund and Request for Abatement
8
Internal Revenue Service. Administrative Penalty Relief
9
Internal Revenue Service. Penalty Relief
10
Internal Revenue Service. Penalty Relief for Reasonable Cause
11
Internal Revenue Service. Interest Abatement
12
Office of the Law Revision Counsel. 26 U.S. Code 6511 – Limitations on Credit or Refund
13
Internal Revenue Service. Abatement and Suspension of Underpayment Interest
14
Internal Revenue Service. Penalty Appeal
15
Taxpayer Advocate Service. Submit a Request for Assistance