IRS Notice CP518: Final Notice — Unfiled Return

What does an IRS CP518 notice mean?

A CP518 is the final reminder that the IRS still has no record of a required return. It follows earlier requests such as a CP516 and signals that the IRS is about to act on its own. The notice gives you a last opportunity to file before the agency prepares a Substitute for Return.

Why did you receive a CP518?

Prior notices asking you to file the missing return went unanswered, and the IRS's records still show income that requires a return for the year cited.

How to respond to a CP518 notice

File the delinquent return immediately if it is owed; doing so lets you claim the deductions and credits a Substitute for Return would omit. If you genuinely had no filing obligation, respond promptly with an explanation and supporting documents. Consider professional help if multiple years are involved.

What happens if you ignore it?

The IRS will file a Substitute for Return using only third-party income data, generally producing the highest possible tax, then assess it and begin collection. You lose the chance to reduce the liability with legitimate deductions unless you later file your own return.

Common resolutions

• File immediately
• Respond with an explanation

Related IRS notices

• CP516 — Unfiled Tax Return — Request to File
• CP59 — Unfiled Return Inquiry
• CP63 — Refund Held — Unfiled Returns
• CP88 — Refund Held — Delinquent Return