How to Fax a Letter 12C Response with Form 8962
A letter arrived, your refund has not, and the letter is asking for a form you have never heard of. That is Letter 12C, sometimes printed as Letter 0012C, and the good news is that it is not an audit and not an accusation. It is a processing request. Your return is sitting suspended until the IRS receives one missing piece.
📌 Use the fax number printed on your own letter, not one from a search result. Letter 12C provides a fax number for exactly this purpose, and it routes to the team holding your suspended return. Numbers published online for this vary, and IRS staff themselves have given out conflicting ones, so the letter in your hand is the authoritative source.
Why You Got It
The most common trigger by far is a missing Form 8962 where the IRS holds a Form 1095-A showing Marketplace health coverage. If you bought insurance through HealthCare.gov or a state exchange and received advance payments of the premium tax credit paid directly to your insurer, those payments have to be reconciled on your return. If Form 8962 was not attached, the return cannot be finished.
Letter 12C is used for other gaps too: withholding the IRS cannot verify against its wage records, a missing schedule, unverified income, or a missing signature. Whatever the reason, the letter lists the specific items, and those are the only things you should send.
The Deadline, and What It Costs You
The letter prints its own deadline, typically 20 days from the date at the top. That is a short window, and it is the reason people end up faxing rather than posting.
Your refund stays frozen until the IRS has what it asked for, so speed is not just about the deadline, it is about your money. Once the response is processed, the IRS says a refund typically follows about six to eight weeks after it receives all the necessary information.
If you genuinely cannot gather one item in time, send what you do have with a short note explaining what is still coming, rather than sending nothing at all.
The Mistake That Costs Weeks
Do not file Form 1040-X. This is the single most common error in responding to a 12C, and the IRS states it directly: you do not need to amend your return, and there is no need to submit an amended return. Filing one sends your case down a much slower path.
What you do instead is complete the missing form on its own, Form 8962 in most cases, and send it back. The IRS then uses it to finish processing your original return.
Where Form 1095-A Comes From
Not from the IRS. The Marketplace is required to send it to you by 31 January for the applicable tax year, and if you did not receive it or have lost it, you log in to your HealthCare.gov or state Marketplace account or contact the Marketplace directly.
The IRS cannot answer questions about the information on your 1095-A, cannot reissue a missing one, and cannot issue a corrected one. If a figure on it looks wrong, that is a conversation with the Marketplace, not with the IRS. If you enrolled in more than one qualified health plan, you receive a separate 1095-A for each and need all of them.
What to Put in the Fax
A copy of the Letter 12C as page one, so the response routes to your file. Then the completed Form 8962. Then your Form 1095-A. If the letter asks for a recomputed page 2 of your return with your original signatures, include that as well.
Write your name, taxpayer identification number, and the tax year on every page, and include the notice number from the letter. Send only what the letter listed. Unrelated documents slow processing rather than helping it.
A Note on Similar Notices
Letter 12C is not the only IRS communication about premium tax credits, and they are handled differently. A CP06 notice, for example, means the IRS is auditing the premium tax credit you claimed and is holding your refund pending that audit, which carries its own timeline, its own form list, and its own destination. Read the notice you actually received and follow that, rather than assuming all premium tax credit correspondence works the same way. Our complete guide to faxing the IRS covers the general pattern across notice types.
This guide explains how to respond to a processing request. It is not tax advice, and if the underlying numbers are in dispute rather than merely missing, a tax professional is the right next call.
Faxing It for $1.00
1
Read the letter for the exact items
It lists what is needed and prints its own deadline. Send only that. Extra paperwork slows things down.
2
Download your 1095-A from the Marketplace
HealthCare.gov or your state Marketplace. The IRS cannot reissue or correct it.
3
Complete Form 8962, not a 1040-X
Fill in the missing form alone. Do not amend the return.
4
Send at faxforadollar.com for $1.00
Letter on top as page one. Up to 10 pages for a dollar, with a timestamped confirmation.
💡 Put a copy of the Letter 12C itself as the first page of your fax. It carries the notice number and the barcode the IRS uses to route paperwork back to your suspended return, and a response that arrives without it takes longer to match up. Then write your name, taxpayer identification number, and the tax year on every page underneath.
Frequently Asked Questions
What is IRS Letter 12C?
A processing request. The IRS received your return but cannot finish it without something that was missing, and your refund is frozen until that item arrives. It is not an audit and not an accusation. It comes from the processing pipeline rather than from an examiner, so your deductions are not being challenged.
What fax number do I use for Letter 12C?
The one printed on your own letter. It routes to the team holding your suspended return. Numbers published online for this vary considerably, and taxpayers report being given conflicting numbers even by IRS staff, so the letter in your hand is the authoritative source.
Why is my refund on hold after Letter 12C?
Because the return cannot be processed until the missing item arrives. The refund is not denied, it is suspended. Once the IRS receives what it asked for and processes it, a refund typically follows about six to eight weeks later if you are entitled to one.
How long do I have to respond to Letter 12C?
The letter prints its own deadline, typically 20 days from the date at the top. That is short, which is why fax is the practical route. If you genuinely cannot gather one item in time, send what you have with a short note explaining what is still coming rather than sending nothing.
Should I file Form 1040-X in response to Letter 12C?
No, and this is the most common and costly mistake. The IRS states directly that you do not need to amend your return. Complete the missing form on its own and send it back. Filing an amended return sends your case down a much slower path and delays the refund further.
What is the cheapest way to fax a Letter 12C response?
$1.00 at faxforadollar.com for up to 10 pages, with no account and no subscription. A letter copy, Form 8962, and a 1095-A is typically four to six pages, comfortably inside that. A shipping store charges $3 to $5 per page for the same transmission.
Where do I get my Form 1095-A?
From the Marketplace, not the IRS. Log in to your HealthCare.gov or state Marketplace account, or contact the Marketplace directly. They are required to send it by 31 January for the applicable tax year. The IRS cannot reissue it, correct it, or answer questions about what is on it.
What if the information on my 1095-A is wrong?
That is a conversation with the Marketplace, not the IRS. The IRS cannot issue a corrected Form 1095-A or answer questions about its accuracy. Contact the Marketplace to get it corrected, then use the corrected version to complete Form 8962.
What do I actually put in the fax?
A copy of the Letter 12C as page one so it routes to your file, then the completed Form 8962, then your Form 1095-A. If the letter asks for a recomputed page 2 of your return with original signatures, include that too. Send only what the letter listed.
Does Letter 12C mean I am being audited?
No. It comes from the processing pipeline rather than from an examiner, and it is a request for a missing item rather than a challenge to what you claimed. Responding to it does not raise your audit risk. It is genuinely paperwork rather than scrutiny.
Do I need a fax machine to respond?
No. You upload the pages in a browser, type the number from your letter, and pay. Nothing is installed and no phone line is involved. Most people photograph or scan the letter and forms and send from a phone or laptop in a couple of minutes.
Can I upload my response instead of faxing?
It depends on what the letter offers. Some IRS notices provide a document upload option and some do not. Read the response instructions on your specific letter. Where fax is offered, it has the advantage of giving you a timestamp you control rather than a portal receipt you cannot export.
What happens if I do not respond to Letter 12C?
Your return stays unprocessed and the refund stays frozen. Depending on the circumstances the IRS may eventually process the return without the claimed credit, which can mean a smaller refund or a balance owed. Responding is considerably better than letting the deadline pass.
Why did I get Letter 12C if I did not have Marketplace insurance?
Because the letter is used for other gaps too: withholding the IRS cannot verify against its wage records, a missing schedule, unverified income, or a missing signature. Read the response section of your letter, which lists the specific items being requested for your case.
How much does a 6-page fax cost?
$1.00, since up to 10 pages is covered by the base price. Beyond that it is $1.99 for 11 to 25 pages. Most 12C responses fit comfortably in the first tier, and there is no account or subscription attached.
How long after I fax will I get my refund?
The IRS says a refund typically follows about six to eight weeks after it receives all the necessary information, assuming you are entitled to one after the reconciliation. The transmission itself takes minutes; the processing behind it does not.
Should I write anything on the pages themselves?
Yes. Your name, taxpayer identification number, and the tax year on every page, plus the notice number from the letter. Pages get separated in a large processing operation, and an unidentified page cannot be matched back to your suspended return.
Is it safe to fax documents with my Social Security number?
A fax travels point to point to the number dialled rather than sitting on a mail server, which is a large part of why the IRS uses it for this. Check the number against your letter twice, since mistyping it is the real risk. On this service the uploaded file is deleted from the servers once the fax has been sent.
Does the IRS confirm they received my fax?
No. The IRS does not acknowledge faxed responses. Your evidence is the transmission confirmation, which records the destination number, the page count, and the exact date and time. Given the letter carries a short deadline, that email is what proves you met it.
Can I fax on a weekend or after hours?
Yes. The receiving equipment runs continuously and your confirmation records that timestamp, with processing beginning the next business day. If your 20-day deadline falls over a weekend, a Saturday transmission still puts the correct date on the record.
The fax number on my letter keeps giving a busy signal, what now?
That is normal during filing season and reflects volume rather than a wrong number. A failed send is refunded automatically here, so retrying costs nothing. Wait an hour and try again, and try outside US business hours. Do not switch to a different number found online, since only the one on your letter routes to your file.
Can I send more documents than the letter asked for, just in case?
Better not to. Extra, unrelated documents slow processing rather than helping, because someone has to work out what they relate to. Send exactly what the letter lists. If you are unsure whether something is required, the letter's response section is the list to work from.
What is the difference between Letter 12C and a CP06 notice?
They are different processes. Letter 12C is a processing request for a missing item. A CP06 means the IRS is auditing the premium tax credit you claimed and holding your refund pending that audit, with its own timeline, form list, and destination. Read the notice you actually received rather than assuming they work the same way.
Can someone else fax the response for me?
Anyone can transmit the pages. Whether they can discuss your account with the IRS afterwards is a separate matter governed by an authorisation form. A family member pressing send is fine; a family member ringing the IRS to chase it will be turned away unless authorisation is on file.
Will a phone photo of my 1095-A be readable?
It will if you take it properly, and legibility matters because an unreadable figure means another round of correspondence you do not have time for. Lay the page flat in good daylight and fill the frame. PDF is safer where you have it, since the 1095-A carries columns of small figures that photograph badly.
Do you keep a copy of what I send?
No. The file is deleted from the servers once the fax has been sent. You keep your own copy and the confirmation email, which records the destination, page count, and transmission time. Keep both until the refund actually arrives.
I enrolled in more than one Marketplace plan. What do I send?
You receive a separate Form 1095-A for each qualified health plan policy, and you need all of them to complete Form 8962 correctly. If any are missing, get them from your Marketplace account before filing the form rather than submitting an incomplete reconciliation.
How long should I wait before chasing it up?
Give it several weeks. Calling during filing season means a long hold for information that will not have updated yet, and the refund itself takes six to eight weeks after processing. If a couple of months pass with nothing, the exact transmission date from your confirmation makes that call far more productive.
What if reconciling the credit means I now owe money?
That is a different problem from the one this page solves, and a real possibility if your actual income was higher than the Marketplace estimate. Respond to the letter first, since an unanswered 12C leaves the return unprocessed either way. Then speak to a tax professional about payment options, because the IRS has processes for balances people cannot pay immediately.
Form 8962 completed and 1095-A to hand?
Use the fax number printed on your letter, send it for $1.00 with the letter on top, and keep the timestamped confirmation.
Send a Fax, $1