What the IRS says: “Final reminder: the IRS has no record of your return and may file a substitute return or take other action.” Here’s what it actually means, your deadline, and exactly how to respond.
End of the polite phase. After CP518 the IRS can build a substitute-for-return from raw 1099/W-2 data — single status, zero deductions, zero basis — then assess and collect on it (CP3219N, then the balance chain). Filing your real return, even late, almost always beats the SFR math.
Notice family: Refund Holds & Unfiled Returns — Your refund is frozen or the IRS has no return on file for a year it expected one. These resolve by filing, verifying, or sending exactly the documents requested — silence makes them worse.
File the real return NOW — it supersedes the SFR process at any stage before assessment
Can't reconstruct records: wage & income transcripts rebuild most of it
Already filed: proof via Form 15103 immediately
Multiple years: prioritize refund years (3-year expiry) and the biggest income years
The return itself is the response. A cover letter noting the CP518 and requesting penalty consideration (reasonable cause for the delay) travels with it.
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.
Final reminder: the IRS has no record of your return and may file a substitute return or take other action. In practice: End of the polite phase. After CP518 the IRS can build a substitute-for-return from raw 1099/W-2 data — single status, zero deductions, zero basis — then assess and collect on it (CP3219N, then the balance chain). Filing your real return, even late, almost always beats the SFR math.
There is no fixed response deadline on this notice, but acting promptly keeps your options open. The respond-by date printed on your own notice always controls.
The return itself is the response. A cover letter noting the CP518 and requesting penalty consideration (reasonable cause for the delay) travels with it.