IRS Letter 12C
Letter 12C: the IRS needs more information to process your return
Letter 12C means the IRS cannot finish processing your individual return until you send it something: a missing or corrected form or schedule, or proof of an amount or a number on the return. You have 20 days to respond.
What the letter can ask for
The letter itself says which of these it needs. Read it carefully before you gather anything.
- Missing or corrected forms or schedules that support entries on your Form 1040 or 1040-SR.
- Verification of income, withholding or credit amounts.
- Verification of taxpayer identification numbers or Social Security numbers.
How to respond
Send the information requested within 20 days. Respond even if you disagree, with a clear explanation of what you disagree with.
Do not file Form 1040-X. The letter is part of processing the return you already filed, and an amended return is not the way to answer it.
Once the IRS has your response, it says any refund due follows in about six to eight weeks.
Avoiding it next year
The IRS’s advice is to include complete information supporting your entries, use the correct forms and schedules, check every Social Security number and ITIN on your tax documents, and keep copies of your returns, supporting documents and any correspondence with the IRS.
Want a second pair of eyes on it?
USTAXX can check the notice against the return it refers to. Where the answer is a return — an amended return, a missing year, a corrected form — we prepare it, and you sign and send your own reply. We are an IRS Authorized e-file provider and work with clients remotely through a secure portal, by phone or video, and in person at our office in Naperville, IL.
Questions people ask
How long do I have to respond to Letter 12C?
Twenty days. Send the information the letter asks for within that time, and respond even if you disagree, explaining what you disagree with.
Should I file an amended return for Letter 12C?
No. The IRS says not to file Form 1040-X; send the specific information the letter asks for instead.
When will I get my refund after responding?
The IRS says about six to eight weeks after it receives your response.
Where these rules come from
General information, current when written, not advice about your situation. Fees and forms change; the official pages above are the authority.