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Official form guide
Form 13979: 13979
IRS Form 13979 is the Amended U.S. Individual Income Tax Return form used to correct errors or make changes to a previously filed Form 1040, 1040-SR, or 1040-NR. You should file this form when you discover mistakes on your original tax return that affect your tax liability.
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IRS Form 13979 - 13979
IRS Form 13979 is the Amended U.S. Individual Income Tax Return form used to correct errors or make changes to a previously filed Form 1040, 1040-SR, or 1040-NR. You should file this form when you discover mistakes on your original tax return that affect your tax liability.
Risk Radar
Scan points- 1Amending returns after the deadline may result in loss of refunds or additional penalties.
- 2Missing the 3-year filing deadline for amendments
- 3Incorrectly calculating the difference between original and amended returns
- 4Failing to attach required supporting documentation
- 5Not updating state tax returns when amending federal
Plain English
This form lets you fix mistakes on your tax return after you've already filed it. Common reasons include incorrect income, deductions, or filing status that would change your tax amount.
Submission Date
- Filing date: 2025-09-29 22:10:18
- Preparation window: collect IDs, supporting records, and signatures in advance.
- Final review: verify names, dates, and required fields before submission.
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What this form is for
- Use this form when you discover mathematical errors, forgot to claim certain credits, or need to change your filing status
- Do not use this form to simply add additional documents to your original return
- Check Form 1040-X instructions to determine if you need to file an amended return
Form selector
Use this form or another form?
Correcting only W-2 or 1099 information
The IRS may make these corrections automatically
✓ Verify if the correction affects your tax liability
Reporting unreported foreign income
Failure to report can result in significant penalties
✓ Ensure all required international disclosures are included
Claiming missed Earned Income Tax Credit
This credit has specific eligibility requirements
✓ Confirm your income and qualifying child information
Correcting business income/loss
Business income changes may trigger additional review
✓ Maintain detailed records of the original error
Deadline or filing window
Amended returns must generally be filed within 3 years of the original return's due date, or within 2 years from the date you paid the tax, whichever is later. If you're claiming a refund, file within 3 years of the original return due date (including extensions) or within 2 years of the date you paid the tax, whichever expires later. The IRS typically processes amended returns within 8-12 weeks.
- —Original tax liability | Amended tax liability - Original tax liability | Tax difference | Ensure you account for any estimated payments already made
Checklist
What you need before filling it out
Income changes
W-2, 1099, or other income statements · Box 1 of W-2, Box 7 of 1099-MISC
Deductions
Receipts, statements, or records · Supporting documentation for each deduction
Credits
Eligibility documents, prior year returns · Credit-specific worksheets or forms
Filing status
Marriage certificates, divorce decrees · Personal information section
Dependents
Birth certificates, Social Security cards · Dependents section on return
Before you submit
- 1Verify all personal information matches original return
- 2Double-check calculation of tax differences
- 3Attach all necessary supporting schedules and documentation
- 4Ensure both spouses sign if filing jointly
- 5Make a copy of the complete package before mailing
- 6Check current IRS mailing address for your location
- 7Include payment if additional tax is owed
- 8Use certified mail with return receipt requested
- 9Confirm form edition matches tax year being amended
How to file this form
- 1Obtain the correct edition of Form 13979 for the tax year being amended
- 2Complete Form 13979 explaining each change from the original return
- 3Attach any required schedules (Schedule 1, 2, 3, etc.) supporting the changes
- 4Mail the complete package to the appropriate IRS address with payment if owed
- 5Track processing time which typically takes 8-12 weeks
- 6Wait for IRS acknowledgment and any resulting refund or additional tax bill
Known limitations
- 1Cannot be used to change tax years or correct original returns filed more than 3 years ago
- 2Processing times can extend beyond the standard 8-12 weeks during peak periods
- 3Amending one year may affect your eligibility for benefits or credits in subsequent years
- 4State tax returns generally require separate amendments when federal returns are amended
- 5Electronic filing is not available for amended returns; must be mailed
Field map
Compact field-by-field guide
General Info
2 items
Full legal name and taxpayer identification number (SSN or EIN).
Current mailing address.
Details
2 items
Complete all applicable sections of this form according to the official IRS instructions.
Enter the relevant dollar amount if this form involves tax calculation.
Certification
1 items
Read and acknowledge any certifications required by this form.
Signatures
1 items
Sign and date. Unsigned forms cannot be processed.
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Fillable formOpen in Editor->The current edition is Form 13979 (2023) for tax year 2023 amendments. Check IRS.gov for the most recent version before filing.
What changed or needs a fresh check
- Edition date: Verify you're using the correct year's form matching the tax year being amended
- Fee: No filing fee for Form 13979, but additional tax may be due
- Mailing address: Changes based on your state and whether payment is included
- Instructions: Always refer to the instructions for the specific tax year
- State requirements: Some states require separate amended returns
Quick Facts
Downloads
After you file
- 1Keep a complete copy of the filed amended return and all supporting documents
- 2Track the 8-12 week processing timeline and follow up if no response
- 3Update your state tax return if the federal amendment affects state taxes
- 4Adjust estimated tax payments for the current year if the amendment affects tax liability
- 5Monitor IRS account online for processing status and any adjustments
- 6Respond promptly to any IRS notices requesting additional information
Sources
- SRCForm purpose: Amended U.S. Individual Income Tax Return
- SRCFiling deadline: Generally 3 years from original return due date or 2 years from tax payment
- SRCProcessing time: Typically 8-12 weeks
- SRCElectronic filing: Not available; must be mailed
- SRCState requirements: Generally require separate amended returns
- SRCDocumentation needed: Varies based on nature of changes
Common confusion points
When to file vs. when not to file
Many taxpayers amend for minor errors that don't affect tax liability
→ Only amend if the change impacts your tax amount or eligibility for credits
Original return vs. amended return
The amended return shows both original and corrected figures
→ Clearly indicate which amounts are original and which are amended
Deadline confusion
Different deadlines apply for claiming refunds vs. paying additional tax
→ Verify which deadline applies to your specific situation
State amendment requirements
Not all states automatically conform to federal amendments
→ Check your state's requirements separately
Third-party preparer involvement
Some preparers charge extra for amendments
→ Confirm who is responsible for filing and follow-up
Workflow map
Related forms and next steps
Before
Current
Often used with
⚠ If something goes wrong
- IRS Form 911 (Taxpayer Assistance Request), Taxpayer Advocate Service
Source transparency
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