The IRS cannot audit or pursue a tax year forever. Federal law sets time limits, often called statutes of limitations, for three separate things: how long the IRS has to assess additional tax, how long it has to collect tax once it is assessed, and how long you have to claim a refund. Each clock starts at a different point and can be paused or extended for different reasons.
The assessment period (ASED)
Assessment is the formal recording of a tax amount on your account. The deadline is called the Assessment Statute Expiration Date, or ASED. The IRS explains the rules this way:
- Three years. The IRS can usually assess within 3 years after the return was due, including extensions, or within 3 years after it received your return if you filed late, whichever is later. A return filed before the due date is treated as filed on the due date.
- Six years. If you leave out income that you should have reported and it is more than 25% of the gross income shown on the return, the period becomes 6 years from the date you filed. A separate six-year rule applies when the omitted income relates to foreign financial assets and exceeds $5,000.
- No limit. The IRS can assess at any time if you file a false or fraudulent return, or if you do not file a valid return.
The IRS can also ask you to sign a consent that extends the assessment period, often during an audit or before an appeal. You can negotiate the proposed extension or refuse, but the IRS says that if you decline, the auditor decides based on the information provided. The decision is worth a conversation with your representative.
What pauses the assessment clock
- A notice of deficiency (90-day letter) suspends the period from the day after it is mailed until 60 days after a final Tax Court decision.
- Certain bankruptcy filings suspend it.
- If the IRS prepares a substitute return for you because you did not file, the three-year assessment clock does not start. Filing your own return afterward starts it. See unfiled tax returns.
The collection period (CSED)
Once tax is assessed, the IRS generally has 10 years to collect it, including penalties and interest. The deadline is the Collection Statute Expiration Date, or CSED. One taxpayer can have several assessments, each with its own CSED.
To find yours, look at the transactions section of your account transcript. Each assessment has a three-digit transaction code with a date beneath it that is generally the CSED plus any added time. Our page on tax transcripts shows how to get one.
What pauses or extends the collection clock
| Event | Effect, as the IRS describes it |
|---|---|
| Offer in compromise | Suspended while pending, plus 30 days after a rejection and during a timely appeal |
| Installment agreement request | Suspended while the request is under review and during any appeal; a rejected or withdrawn request adds 30 days |
| Collection due process hearing | Suspended until the request is withdrawn or Appeals' decision is final |
| Innocent spouse request | Suspended while pending, with an additional 60 days after |
| Bankruptcy | Suspended during the case; adds 6 months at the end |
| Living outside the U.S. | Suspended for an absence of six continuous months or more |
When the CSED passes, the IRS can no longer collect that balance. Never assume it has passed without checking, because suspensions can move the date further out. See offers in compromise and collection due process hearings for how those programs affect timing.
The refund period
To get a refund, you generally must claim it within 3 years of filing the original return or 2 years of paying the tax, whichever is later. If you never filed, the IRS says you must file within 3 years of the return due date to claim a refund of withholding or estimated tax. After that, the refund is lost and cannot be applied to another year. Read unfiled tax returns if you have missed years.
How the limits relate to your records
The IRS tells taxpayers to keep records for 3 years from filing, 6 years if you may have omitted more than 25% of gross income, and indefinitely if you did not file or filed a fraudulent return. Employment tax records should be kept for at least 4 years. See our guide on how long to keep tax records.
How we can help
We can calculate the likely assessment and collection dates from your filing history and IRS transcripts, explain what each means for an open audit or balance, and advise you before you sign a consent. This is general information and your dates depend on your own account. Learn more about IRS audit representation or contact us.
Frequently asked questions
Does the 3-year limit apply if I never filed?
No. The IRS says there is no time limit to assess tax when you do not file a valid return. Filing the return starts the clock.
Is the 10-year collection clock the same as the audit clock?
No. The assessment period limits how long the IRS has to determine the tax. The collection period begins after the tax is assessed. They run on separate schedules.
Can the IRS collect after 10 years?
Not for an assessment whose CSED has expired, but the date can be extended by events such as offers, hearings or bankruptcy. Check your transcript.
Does a payment plan stop the collection clock?
A pending request suspends it, along with an appeal of a rejection. An agreement that is already in effect is not on the IRS's list of suspending events, so the clock generally keeps running. Check your own account before relying on a date.
Official sources
- IRS: Time IRS can assess tax
- IRS: Time IRS can collect tax
- IRS: Topic no. 305, Recordkeeping
- IRS: Filing past due tax returns
This page is a plain-language summary. The official source controls if there is any difference.
General information only, not tax, legal or accounting advice for your situation. Rules, limits and deadlines change; confirm the current rules with the official source or a qualified professional before you act. Reading this page does not create a professional relationship with CPA Tax Payroll and Accounting Corp.