U.S. · IRS notices
IRS CP40 notice explained.
A notice that your unpaid tax balance was assigned to a private collection agency.
CP40 tells you the IRS assigned your unpaid tax account balance to a private collection agency. The notice has the name and contact information of that agency, which you’ll need to complete the two-party verification process. The IRS page says to work with the assigned agency to resolve the unpaid account, or to pay the balance now. It prints no response date; check the notice itself.
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
“We assigned your unpaid tax account balance to a private collection agency.” The IRS page says the notice contains the agency’s name and contact information, which you’ll need to complete the two-party verification process. In its FAQ the IRS says it is required by law to contract with private collection agencies to assist in collecting certain unpaid tax accounts.
What the IRS page says to do
Work with your assigned private collection agency to resolve your unpaid account, or pay your balance now (the IRS page points to its payments page for ways to pay the IRS directly). The IRS page says the agency maintains the security and privacy of your tax information and, before assisting you, will ask for your name and address of record and perform two-party verification using the Taxpayer Authentication number provided in your notice.
Checking the agency is real
The IRS FAQ says your notice contains the name and contact information of the agency assigned your account, that the names of all agencies under contract with the IRS are on the private debt collection program site, and that the agency will also send a letter confirming assignment of your tax account.
If you can’t pay in full
The IRS FAQ says the private collection agency will work with you to set up a payment plan if you can’t pay in full when contacted.
More from the IRS
The IRS page lists the private debt collection program site and Publication 4518, What You Can Expect When the IRS Assigns Your Account to a Private Collection Agency.
More IRS notice pages
Other pages in this set: CP2057, CP215, CP277, CP32A, CP45, CP518, 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 CP40 notice, Internal Revenue Service: what the notice is, what to do, FAQ. Page last reviewed or updated June 25, 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 CP40 notice mean?
The IRS assigned your unpaid tax account balance to a private collection agency. The notice has the agency’s name and contact information, needed for two-party verification.
Why was my account transferred to a private collection agency?
The IRS page says the IRS is required by law to contract with private collection agencies to assist in the collection of certain unpaid tax accounts.
How does the IRS say I can check the agency is under contract with the IRS?
The IRS page says your notice names the agency, the names of all contracted agencies are on the private debt collection program site, and the agency will also send a letter confirming assignment of your account.
What will the agency ask me for?
The IRS page says that before assisting you the agency will ask for your name and address of record and perform two-party verification using the Taxpayer Authentication number in your notice.
Can I pay over time after a CP40?
The IRS page says yes: the private collection agency will work with you to set up a payment plan if you can’t pay in full when contacted.
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.