IRS Notices
Letter 12C IRS: Return Information Request and What to Do (2025)
The short answer: a Letter 12C from the IRS means your return is missing information the IRS needs to finish processing it. It is not a bill or an audit. You usually have about 20 days to mail or fax the documents requested — and your refund stays on hold until you do.
⏱ Your deadline: the date printed on the letter — typically 20 days from the notice date. Respond by then to keep your return moving. Miss it and the IRS may process your return without the credit or item in question, which can shrink your refund or create a balance due.
Why you got a Letter 12C from the IRS
You filed a return, the IRS started processing it, and a piece of the puzzle is missing. That's all a Letter 12C is — a request to fill in the gap. The letter spells out exactly what the IRS needs, and processing is paused until you send it. The IRS explains this in its own guide, Understanding Your Letter 12C.
The most common reasons the IRS sends this return information request are:
- Missing Form 8962 and Form 1095-A. If you or a dependent had a Health Insurance Marketplace plan, the IRS needs Form 8962 to reconcile the premium tax credit. This is the single most frequent cause.
- Income or withholding that doesn't match. The IRS may ask for copies of your W-2s, 1099s, or other proof of the federal tax withheld that you claimed.
- A missing form or schedule. Something you referenced on the return didn't make it into the file.
- A missing signature or supporting document for a credit or deduction.
Notice what a Letter 12C is not: it's not an audit, it's not a penalty, and nobody is accusing you of anything. It's a paperwork gap. If you're still unsure why you got a letter from the IRS, the letter's first paragraph names the exact item it needs.
What happens if you ignore it
A Letter 12C won't trigger wage garnishments or bank levies — it's not a collection notice. But ignoring it still costs you, and the consequences build in a predictable order:
- Your return stays frozen. Nothing finishes processing, and any refund you're owed sits untouched.
- Your refund is delayed indefinitely. The hold doesn't lift on its own — only your response releases it.
- The IRS may process without the item. Past the deadline, the IRS can finish your return without the credit it questioned. If that credit was part of your refund, your refund shrinks.
- A balance due can appear. If a disallowed credit flips your return from a refund to taxes owed, the IRS will bill you — and that is the start of the collection sequence, beginning with a CP14 notice.
In short: the fastest, cheapest move is always to answer the letter on time. Everything bad downstream comes from silence.
First: make sure the Letter 12C is real
Before you mail anything, take a few minutes to confirm the letter is genuine. Scammers copy IRS letters, and a 12C asks you to send personal tax documents — exactly what an identity thief wants.
- It arrives by postal mail only. The real IRS does not request these documents by email, text, or phone call.
- It never asks for payment. A Letter 12C asks for tax forms, not money. Anyone demanding gift cards, wire transfers, or a payment app is a criminal.
- It has a fax number and mailing address printed on it. Use only those — don't trust a number someone gives you over the phone.
- Verify it yourself. Log into your IRS online account to confirm a notice was issued.
If you want a second opinion, our guide on how to tell if an IRS letter is real walks through every check. A Letter 12C is different from an identity-verification letter like the 5071C letter — but both can be confirmed the same way.
How to respond to Letter 12C, step by step
- Read the letter twice. It names the exact form, schedule, or document the IRS needs. Underline it so you don't send the wrong thing.
- Gather the documents. If it's the premium tax credit, pull your Form 1095-A and complete Form 8962. If it's withholding, collect your W-2s and 1099s.
- Write the calculations if asked. Some letters want a corrected figure or a completed form, not just a copy. Follow the instructions exactly.
- Include a copy of the Letter 12C. Put it on top so the IRS can match your reply to the right file.
- Fax or mail by the deadline. Faxing to the number on the letter is usually faster than mail. If you mail it, use a method with tracking and keep proof of the send date.
- Keep copies of everything — the letter, your response, and your proof of delivery.
- Wait six to eight weeks. That's the IRS's general processing window after it receives your reply. Then check your refund status or your online account.
If the missing item changes your refund — say a disallowed credit could turn your refund into taxes owed — it's worth knowing your options before that happens. Our guide on whether the IRS will take your refund for back taxes explains how a refund can be applied to an older balance.
Not sure what your Letter 12C is asking for?
Send us a photo of it. An experienced tax professional will tell you exactly what the IRS needs and how to send it — free, confidential, and no pressure.
Letter 12C questions, answered
Is a Letter 12C from the IRS bad?
No. A Letter 12C is not a bill, an audit, or a penalty. It simply means the IRS needs one or more missing pieces of information before it can finish processing your return. The only real risk is ignoring it, which delays your refund and can cause credits to be disallowed.
What happens if I don't respond to Letter 12C?
Your return stays unprocessed and your refund stays frozen. If you don't reply by the deadline, the IRS may process the return without the credit or item in question, which can shrink your refund or turn it into a balance due. Responding on time is the fastest way to avoid that.
Why does the IRS need Form 8962 with my Letter 12C?
If anyone on your return had a Marketplace health plan, the IRS needs Form 8962 and your Form 1095-A to reconcile the premium tax credit. This is the single most common reason for a Letter 12C. Send both forms together so the IRS can match the advance payments to your actual credit.
How long does it take the IRS to process my return after I reply to Letter 12C?
The IRS generally says to allow six to eight weeks after it receives your response. Faxing the documents to the number on your letter is usually faster than mailing them. Once processed, any refund you're still owed is released.
How do I know my Letter 12C isn't a scam?
A real Letter 12C arrives by postal mail, never by email, text, or phone call, and it never asks for gift cards, wire transfers, or payment apps. It asks you to mail or fax tax documents, not to pay money. You can confirm any letter by logging into your account at IRS.gov.
This guide is general information, not tax or legal advice for your specific situation. Eligibility for IRS programs depends on individual facts and circumstances; no outcome is guaranteed.