IRS Letter 12C: What It Means and What to Do
The IRS started processing your return but needs more information to finish. It may be a missing form or schedule, proof of income, withholding, or credits, or confirmation of a Social Security number or ITIN. Once you send it, the IRS says any refund is usually sent about 6-8 weeks later.
Letter 12C key facts
| Official name | Letter 12C: We need more information to process your individual income tax return. |
|---|---|
| Who gets it | Individuals |
| Severity | 3 of 5: Moderate: respond by the deadline Your return is paused, with any refund held, until you send the requested information within a short 20-day window. |
| Response window | "Send the information we requested within 20 days." Respond even if you disagree. Check your letter for the exact response date. |
| Deadline basis | The date printed on the letter. The IRS page gives a number of days but doesn't say when the count starts. |
Severity is RAHA Financials' own 1 to 5 rating of how urgent the notice usually is. It is not an IRS classification.
How long do I have to respond to Letter 12C?
Use the date printed on your notice. It is typically 20 days from the notice date. Enter the notice date to see an approximate date.
The date printed on your notice always controls. Open Letter 12C in the IRS Notice Decoder.
Why did I get Letter 12C?
Common reasons include:
- A missing Form 8962 when advance premium tax credit payments were made for your Marketplace health coverage
- Missing or incomplete forms or schedules supporting entries on Form 1040 or 1040-SR
- Income or withholding amounts that need verification (for example, W-2 or 1099 figures)
- Credit amounts that need support
- A taxpayer identification number or Social Security number that needs verification
What should I do?
- Read your letter carefully to see exactly what information the IRS needs.
- Gather the missing forms, schedules, or proof it asks for.
- If the letter is about the premium tax credit, complete Form 8962 and include a copy of your Form 1095-A from the Marketplace.
- Send the information within 20 days, by fax to the number in your letter or as the letter directs.
- Respond even if you disagree, with a clear explanation of what you think is wrong.
- Don't file Form 1040-X; the IRS says it will use your response to process your original return.
- Allow about 6-8 weeks after the IRS gets your response for any refund.
What documents do I need?
- The Letter 12C
- A copy of your tax return for the year on the letter
- Form 1095-A and a completed Form 8962, if the letter asks about the premium tax credit
- Forms W-2, 1099, or other proof of income and withholding the letter asks for
- Any missing schedules or forms that support your return
- Social Security cards or ITIN documents, if identification numbers need to be verified
What should I avoid?
- Don't file Form 1040-X, Amended U.S. Individual Income Tax Return.
- Don't ignore the letter even if you disagree; the IRS says to respond with an explanation.
- Don't miss the 20-day window.
- If you fax your response through an online service, don't skip checking its privacy and security policies, as the IRS advises.
What if I disagree with Letter 12C?
The IRS says to respond to the letter even if you disagree, with a clear explanation of what you disagree with. For the premium tax credit version, it says to send a letter explaining what information you think is in error.
What happens if I ignore Letter 12C?
The IRS says it needs the information to process your return, so processing and any refund may be delayed if you don't respond. For the Form 8962 version, the IRS says that if you don't reconcile, you won't be eligible for advance payments of the premium tax credit or cost-sharing reductions for Marketplace coverage for the following calendar year.
What else should I know about Letter 12C?
Letter 12C is a pre-processing request, not an audit or a bill. The IRS has paused your original return until it gets what's missing. The IRS gives a short window: 'within 20 days.' One common version involves the premium tax credit. If the Marketplace paid advance credits toward your health insurance and your return didn't include Form 8962, the IRS sends a 12C asking for Form 8962 and Form 1095-A. Not reconciling can cost you advance credit payments for the following year's Marketplace coverage. A frequent mistake is filing an amended return; the IRS says not to file Form 1040-X and to send the information in reply to the letter.
Want a professional to handle your Letter 12C response?
IRS Notice Response Plan
Fixed price, quoted before any work startsFixed fee.
- Review of your notice and account transcript
- A written plan: agree, partly agree, or dispute
- Draft response and list of supporting documents
- Deadline tracking so nothing lapses
Letter 12C: frequently asked questions
Should I file an amended return to fix the problem?
No. The IRS says not to file Form 1040-X. After it receives the requested information, it will use it to process your original return.
How long will my refund take after I respond?
The IRS says it will send any refund due about 6-8 weeks after it receives your response.
Why did I get a Letter 12C about Form 8962?
The IRS says this happens when the Marketplace reported advance premium tax credit payments for your coverage but your return didn't include Form 8962 to reconcile them. Send Form 8962 with a copy of your Form 1095-A.
Can I fax my response?
Yes. The IRS says your letter provides a fax number if you want to send the information by fax. If you use an online fax service, review its privacy and security policies first.
What if I disagree with the letter?
You still need to respond. The IRS says to send a clear explanation of what you disagree with.
