IRS Letter 12C: the missing item that is holding your refund

What does IRS Letter 12C mean?

IRS Letter 12C is a processing letter. It says the IRS started working on your Form 1040 or 1040-SR, hit a gap it cannot fill on its own, and stopped. Your refund waits in that stopped state until the gap is filled.

The letter is not an audit and does not by itself mean you owe money. It lists the exact item needed, and it includes a response page. Because the reply window is short, open it the day it arrives and check the date printed at the top, since the 20 days run from that date, not from when you read it.

Letter 12C is one of several reasons a refund can stall. If you are not sure which hold applies to you, start with our overview of a tax refund delayed past the normal window.

Letter 12C missing information: the usual items

The IRS lists three groups of reasons the letter goes out: missing or corrected forms and schedules, verification of income, withholding and credits, and verification of Social Security or taxpayer identification numbers. The table pairs each one with what normally resolves it.

Letter 12C and Form 8962: the premium tax credit case

If you or anyone on your return had health insurance through the Marketplace and advance payments of the premium tax credit were made, you must reconcile them on Form 8962. When that form is missing, incomplete or seems to conflict with your income, a Letter 12C is the IRS's way of asking for it.

To complete Form 8962 you need Form 1095-A, the Health Insurance Marketplace Statement. Column A shows the monthly enrollment premiums, column B the premium of the second lowest cost silver plan, and column C the advance payments made for you. Those three columns feed the monthly lines of Form 8962.

If the Marketplace has not sent your 1095-A, or the figures look wrong, get a copy or correction through your Marketplace account before you reply, and tell the IRS in a short note if that will make you late. An e-filed return that leaves out Form 8962 can also be rejected before it is accepted; that separate problem is covered under reject code F8962-070.

How to respond to Letter 12C

1. Find the letter date and count 20 days forward. Put that date on your calendar.
2. Read the list of requested items and collect only those. Extra, unrelated paperwork slows the reviewer.
3. Place a copy of the letter or its response page on top of your reply.
4. Send the reply to the address or by the method printed on the letter.
5. If you disagree with what the letter says is missing, still reply by the deadline and explain in plain words why.
6. Keep copies of every page and a mailing receipt or tracking number.

What if you miss the 20 days?

Send the information anyway, as soon as you can. If the IRS gets no response, it adjusts your account using what it has, which can reduce the refund or increase the tax you owe.

Refund timing after you reply to Letter 12C

The IRS says it sends any refund due about 6 to 8 weeks after it receives your response. Count from the delivery date of your reply, not from the date you mailed it.

During that time Where's My Refund may keep showing that your return is being processed. Your account transcript is a better signal: a posted TC 846 with a date means the refund has been scheduled.

If the 8 weeks pass with no change, call the number on the letter with your reply copies at hand. When a hold keeps stretching well beyond that, our page on a tax refund delayed 6 months explains escalation and the interest the IRS may owe you.

A Letter 12C is different from a request to prove wages with pay stubs. That request comes as a CP05A notice, and each one needs its own answer if you receive both.