IRS Notice CP11: a math-error bill and a 60-day right
The IRS fixed what it treats as a mistake on your return and billed the difference. You have a statutory right to have the change reversed if you ask in time, and losing that window also loses the route to the Tax Court.
THE CLOCK — 60 DAYS UNDER THE STATUTE; THE NOTICE PRINTS THE DATE
The Internal Revenue Code gives 60 days after a math-error notice is sent to request abatement, and the IRS must then abate the assessment. No levy or court proceeding to collect it may begin during that period. The IRS prints the response date on the notice. If you miss it, the IRS says you lose formal rights to have the change reversed and your right to appeal to the Tax Court.
What the IRS changed, and why it can bill you directly
A CP11 says the IRS corrected one or more mistakes on your return and that the amount you owe has changed as a result. The notice has a section headed with what was changed on the return, and that section is the thing to read first.
Ordinarily the IRS cannot assess additional income tax without first sending a notice of deficiency, which gives 90 days to go to the Tax Court. Math and clerical errors are the exception. The statute lets the IRS correct them and bill the result straight away, provided it explains the error.
In exchange, the law gives the taxpayer a simple remedy. Ask within 60 days and the assessment must be abated. If the IRS still thinks it is right, it then has to use the full deficiency procedure, with the Tax Court route that comes with it.
Checking the change against your return
Many CP11 adjustments are genuine arithmetic or transcription errors and the right response is to pay. Others involve a credit or deduction that was disallowed because a form, a number or a qualifying detail was missing. The difference is visible by putting the notice beside the return.
COMPARE THE NOTICE WITH THE RETURN
- Each line the IRS changed, the figure you reported and the figure it substituted
- Whether a supporting form or schedule was left off the return as filed
- Dependent and filing status details, including identification numbers
- Estimated payments and prior-year overpayments applied to this year, which are a common source of mismatch
- Whether the change affects Massachusetts too, since a federal change usually has to be reported to the state
Keep the envelope and write down the date you received the notice. The 60 days run from when it was sent, not from when you opened it.
Asking for the reversal
The IRS says to contact it by the date on the notice if you disagree, and that the fastest way to resolve many return errors is by telephone. It says it will reverse most changes that increased the amount you owe, that you do not need to give an explanation or documents to request the reversal, and that giving them may resolve the case more quickly.
If it does not receive information supporting the original return, it may forward the case for an audit. The IRS says audit staff will then contact you within six weeks to explain the process and your rights. That is the deficiency procedure the statute requires, and it brings the Tax Court route with it.
Put the request on record. A call is fine, but note the date, the name or badge number of the person you spoke to and what was agreed, and follow up in writing if anything was left open.
CP12: the refund version
A CP12 is issued when the IRS corrects one or more mistakes and the result is a different refund from the one you expected, or a refund when you thought you owed or broke even. If you agree, no response is needed, and the IRS says a refund check should follow in four to six weeks if you do not owe other tax or debts it must collect.
If you disagree, the same rules apply. Contact the IRS by the date on the notice; it will reverse most changes that reduced the refund you requested; and missing the date loses the formal reversal right and the right to appeal to the Tax Court.
For both notices, the IRS says it will still consider supporting documents sent after the date and may reverse the change if it agrees. That is a courtesy rather than a right, and it is the reason to act inside the window rather than after it.
Where this comes from
The statutes behind this page, so you can check any of it rather than take it on trust.
- IRC §6213(b)(1)
- Lets the IRS assess tax arising from a mathematical or clerical error without first issuing a notice of deficiency, provided it sends a notice explaining the error.
- IRC §6213(b)(2)(A)
- A request for abatement filed within 60 days after the notice is sent obliges the IRS to abate. Any reassessment then has to go through the deficiency procedures.
- IRC §6213(b)(2)(B)
- No levy or court proceeding to collect the assessment during the period in which it may be abated.
- IRM 21.5.4
- The Internal Revenue Manual section on math-error procedures, which sets out how these requests are handled internally.
This page explains what the IRS or the Massachusetts Department of Revenue does and cites the statute. It is not advice about your situation, which depends on facts none of this knows. Tell us what your letter says and what date is on it. Please do not send Social Security numbers or tax documents through the form.
Notice CP22A
The IRS has already changed your return and you owe because of it. The notice is the bill for the change, not a proposal, so the first job is to find out exactly what changed and where the change came from.
Notice of Deficiency
The letter that ends the administrative stage. It carries the only window in which you can have a court decide the amount before paying it, and that window is statutory.
Notice CP2000
An automated comparison found income reported to the IRS that does not appear on your return. The proposed tax is frequently much larger than the correct answer, because the computer does not know what anything cost you.
Penalty abatement
Two separate routes with different tests. One depends only on a clean compliance history and is granted administratively. The other depends on what happened and why, and is argued.
Questions about notice cp11.
- How long do I have to dispute a CP11?
- The statute gives 60 days after the notice is sent to request abatement, and the notice prints a response date. The IRS says that if you miss it you lose formal rights to have the change reversed and your right to appeal to the Tax Court.
- Do I need documents to get a math-error change reversed?
- The IRS says you do not need to provide an explanation or documents when you request the reversal, though doing so may resolve the case faster. If it still disagrees, it may send the case to audit, which follows the full deficiency procedure.
- Can the IRS levy during the 60 days?
- No. The statute bars any levy or court proceeding to collect a math-error assessment during the period in which it may be abated. That protection does not stop interest from running on an amount that turns out to be owed.
- What is the difference between a CP11 and a CP12?
- Both report a correction of a mistake on your return. A CP11 means you now owe more. A CP12 means your refund changed, or you have a refund when you expected to owe or break even. The disagreement rules are the same for both.
- Should I file an amended return to dispute a CP11?
- No. The dispute is made by contacting the IRS by the date on the notice. The IRS says to correct your own copy of the return but not to send it in. Form 1040-X is for a separate correction you want to make.
Tell us what the letter says and what date is on it.
Scope and price in writing before anything starts. Where what you need is something we do not do, you will be told that instead.
Please don't send Social Security numbers or tax documents through this form.