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Your IRS CP518 Notice, Explained
Also called: Notice CP518, CP 518, Final Reminder Return Delinquency Notice
Last reviewed 2026-07-12
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What this notice usually means
A CP518 notice is the IRS's final reminder that it has no record you filed a prior-year tax return. It is not a bill by itself, but it warns of what can happen next if the IRS does not hear from you. The IRS may figure out your tax for you using the income information it already has, and penalties and interest can keep adding up on any amount that turns out to be owed. Any refund you are due can also be held up until the return is filed. The IRS decides what happens with your account.
See every source line for this notice
“This is your final reminder; we still don’t have a record that you filed your prior year tax returns.”
“Immediately respond to the notice by:”
“We may determine your tax for you.”
“Penalty and interest may continue to accrue.”
“If you are owed a refund, it may be delayed because of this unfiled return.”
“You don't have to do anything if you filed your tax return within the last 8 weeks.”
What to do now
- 1
Check whether you already filed
If you filed the return within the last 8 weeks, the notice says you do not need to do anything else right now.
- 2
File the return with Form 15103 if you have not
Fill out Form 15103. Send it with your signed tax return to the address on your notice.
- 3
Explain why you do not have to file, if that is true
Form 15103 also lets you explain why you are not required to file for that year, if that applies to you.
- 4
Send your response the way your notice allows
You can mail it or fax it to the number on your notice. If you only send Form 15103, you can submit it online.
- 5
Call the number on your notice if you disagree
Have your notice and account information ready when you call to explain why you think the notice is wrong.
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Your notice asks you to respond immediately since this is the final reminder in the series. The IRS explainer page does not list a fixed number of days, so use the response date on your own notice as the real deadline.
We did not verify a general deadline for this letter. Your letter shows the real date.
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Sources
- Internal Revenue Service (IRS.gov)Retrieved 2026-07-12
Last reviewed 2026-07-12
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