U.S. · IRS notices
IRS CP518 notice explained.
A final reminder that the IRS has no record of your prior-year tax return.
CP518 is a final reminder: the IRS still doesn’t have a record that you filed your prior year tax returns. The IRS page says to respond immediately by filing your return with a completed Form 15103, Form 1040 Return Delinquency, or by completing Form 15103 to explain why you don’t have to file, and returning it to the address on your notice. The IRS page prints no calendar date.
Compare IRS CP notices
Result
CP notices at a glance
| Notice | What the IRS page says it is | Response, as the IRS page states it |
|---|---|---|
| CP40 | The IRS assigned your unpaid tax account balance to a private collection agency. The notice contains the agency’s name and contact information, which you need for the two-party verification process. | Work with the assigned private collection agency, or pay the balance now. The IRS page prints no response date. |
| CP2057 | You may need to file an amended return. The IRS received information that was not reported on your tax return. | File an amended return if the information is correct. If it is wrong, contact the business or person who reported it. No date is printed on the IRS page. |
| CP215 | The IRS charged the taxpayer a civil penalty. The notice explains the due date, amount due and payment options. | Read the notice; contact the IRS if you disagree. The due date is the one printed on your notice. |
| CP277 | The IRS accepted the Form 8832, Entity Classification Election. Acceptance is based on the accuracy of the information provided. | File the return that matches your entity classification election, notify the IRS if your address changed, and keep the notice. |
| CP32A | The taxpayer did not cash a refund check and it expired. | Call the number on the notice to get a new check; destroy the old check if you still have it. |
| CP45 | The IRS could not apply the taxpayer’s overpayment to next year’s estimated taxes as requested. | Read the notice, update your own copy of the return, and adjust current-year estimated payments. No date is printed on the IRS page. |
| CP518 | A final reminder: the IRS still has no record that the taxpayer filed prior year tax returns. | Respond immediately: file the return with Form 15103, or complete Form 15103 to explain why you don’t have to file. |
| CP297 | The IRS is giving notice of its intent to levy certain assets for unpaid taxes. The taxpayer has the right to a Collection Due Process hearing. | Read the notice, pay what you owe or request a payment plan. To disagree, request a Collection Due Process hearing on Form 12153. |
| CP3219N | The IRS didn’t receive a tax return and calculated tax, penalty and interest from income reported by third parties. The CP3219N is a Notice of Deficiency (90-day letter). | Challenge: petition the Tax Court within 90 days (150 outside the U.S.) of the notice date. Otherwise sign and return the response form and pay, or file your return by the date shown. |
| CP259 | The IRS shows the taxpayer is required to file a tax return for the periods on the notice but hasn’t. | File the required business return immediately; if you think you’re not required to, complete the Response form. You may disregard it if you filed within the last four weeks with the same name and EIN. |
| CP256 | An installment payment is due for the taxpayer’s IRC section 965 tax liability. | Make your annual installment payment on time as required by IRC section 965(h). The due date is the one on your notice. |
The notice number is printed on the notice itself, usually in the top right corner. Use the number exactly as printed; the table follows the IRS page for each number.
What the IRS says the notice is
“This is your final reminder; we still don’t have a record that you filed your prior year tax returns.”
What the IRS page says to do
Immediately respond to the notice by filing your tax return with the completed Form 15103 to explain why you’re filing late or that you’ve already filed, or by completing Form 15103 to explain why you don’t have to file. Return the completed Form 15103, and the tax return if applicable, to the address on your notice. You can fax it to the number in the notice using a fax machine or online fax service; the IRS page warns to understand the fax service’s privacy and security policies. If you’re only sending Form 15103 to explain why you don’t have to file, you can submit it online with an IRS Online Account.
If the IRS doesn’t hear from you
The IRS page says it may determine your tax for you, penalty and interest may continue to accrue, and a refund you are owed may be delayed because of the unfiled return.
If you just filed
The IRS FAQ says you don’t have to do anything if you filed your tax return within the last 8 weeks. If you didn’t file, or it has been more than 8 weeks, complete Form 15103, make sure the name, Social Security number and year match your return, and send a signed, dated copy of the return with the form.
If you disagree or can’t pay in full
The IRS FAQ says to call the toll-free number on your notice, with your notice and account information available, or respond by returning Form 15103. If you can’t pay the full amount when you file, it says to file your return anyway and request a payment plan. The IRS page also says it accepts returns electronically for the 2 most recent prior years, through an e-file provider that offers the service.
More IRS notice pages
Other pages in this set: CP40, CP2057, CP215, CP277, CP32A, CP45, CP297, CP3219N, CP259, CP256. For the codes on an IRS account transcript, see the IRS transcript codes lookup. For how interest and penalties are worked out on a balance, see the IRS penalty and interest calculator.
Sources
- Understanding your CP518 notice, Internal Revenue Service: what the notice is, what to do, FAQ. Page last reviewed or updated April 1, 2026. Read November 2, 2026.
This page restates what the IRS page says and adds nothing beyond it: no timelines, outcomes or advice that the IRS page does not state. The IRS can change a notice page at any time; the notice you received controls, including its response date and contact details.
Frequently asked questions
What does an IRS CP518 notice mean?
It is a final reminder: the IRS still doesn’t have a record that you filed your prior year tax returns.
What does the IRS say to do after a CP518?
Respond immediately by filing your tax return with a completed Form 15103, or by completing Form 15103 to explain why you don’t have to file, and return it to the address on the notice.
What if I don’t respond to a CP518?
The IRS page says it may determine your tax for you, penalty and interest may continue to accrue, and a refund may be delayed because of the unfiled return.
What if I filed my return recently?
The IRS page says you don’t have to do anything if you filed within the last 8 weeks.
What if I can’t pay the full amount when I file?
The IRS page says to file your return anyway and request a payment plan to pay your balance over time.
Not tax or legal advice
This page summarizes IRS notice pages and is not tax, legal or financial advice. It does not tell you how to respond to a notice beyond what the IRS page states. The notice you received controls. A CPA, enrolled agent or tax attorney, or the IRS number printed on your notice, can confirm what applies to you. Everything runs in your browser; nothing you enter is sent anywhere.