What the IRS says: “The IRS needs missing information — a form, schedule or verification — before it can finish processing your return.” Here’s what it actually means, your deadline, and exactly how to respond.
A 12C means processing is frozen, refund included, until you reply. Common asks: Form 8962 (premium tax credit reconciliation), missing W-2 withholding verification, unsigned return, or a missing schedule. The 20-day reply window is short by IRS standards, and the fix is usually a single fax.
Notice family: Underreporter & Audit — The IRS thinks your return doesn't match its records — or wants to examine it. These notices carry hard response deadlines, and a written response with documentation is exactly how they get resolved.
20 days — to reply before processing (and any refund) stalls further.
Counted in calendar days from the notice date. The exact respond-by date printed on your notice always controls — check page 1.
Read exactly which items are listed — send all of them in one reply
Fax to the number on the letter (faster than mail) with the letter's cover sheet on top
Don't file a second return or a 1040-X — that multiplies the delay
Track your refund status ~6-8 weeks after responding
Reply with the documents plus a one-page cover letter listing what's enclosed, your name, SSN placeholder and tax year on every page. Incomplete replies restart the clock — complete ones release the refund.
Describe the notice and your side of it — use placeholders, never your SSN or account numbers (the letter keeps [YOUR NAME]-style fields so you fill in the real details privately before mailing). A mail-ready draft with an enclosure checklist comes back in ~20 seconds.
Your IRS response letter draft will appear here.
The IRS needs missing information — a form, schedule or verification — before it can finish processing your return. In practice: A 12C means processing is frozen, refund included, until you reply. Common asks: Form 8962 (premium tax credit reconciliation), missing W-2 withholding verification, unsigned return, or a missing schedule. The 20-day reply window is short by IRS standards, and the fix is usually a single fax.
You generally have 20 days — to reply before processing (and any refund) stalls further. The respond-by date printed on your own notice always controls.
Reply with the documents plus a one-page cover letter listing what's enclosed, your name, SSN placeholder and tax year on every page. Incomplete replies restart the clock — complete ones release the refund.