When does a 6-year assessment period apply?

When the taxpayer omits gross income exceeding 25% of the gross income stated on the return

When the taxpayer files a joint return

When the taxpayer overstates deductions by more than 25% of the deductions shown on the return

When is there no statute of limitations on assessment?

When no return is filed, or when a false or fraudulent return is filed with intent to evade tax

When the taxpayer is in bankruptcy, because the automatic stay permanently removes the time limit on assessment

What is the general time limit to file a claim for refund?

The later of 3 years from the date the return was filed or 2 years from the date the tax was paid

3 years from the date the tax was paid or 2 years from the date the return was filed, whichever is earlier

A taxpayer files a 2021 claim for refund within 3 years of filing the 2021 return (filed on time without extension). How far back do the payments she can recover go?

Tax paid within 3 years before the claim, plus any extension period

Only tax paid within 2 years before the claim, with no extension period added

What is the refund claim period for a bad debt deduction or worthless security?

7 years from the due date of the return for the year the debt or security became worthless

2 years from the date the tax was paid for the year in which the debt or security became worthless

How long does the IRS generally have to collect tax after it is assessed?

10 years from the date of assessment (the CSED), subject to suspension events

Which event suspends the collection statute of limitations?

Filing an automatic extension to file

Statutes of limitations (assessment, refund, collection)

The IRS generally has 3 years after a return is filed (or its due date, if later) to assess, 6 years if more than 25% of gross income was omitted, and unlimited time for fraud or no return; it then has 10 years to collect, while taxpayers have the later of 3 years from filing or 2 years from payment to claim a refund.

Updated 2026-09-23 · 6 sources · By the EnrolledAgentKit team

Exam part

Part 3

Representation, Practices and Procedures

IRS domain

Representation before the IRS

25 of 85 scored Qs

Tax year tested

2025

2026-27 SEE

Practice questions

10 free below

The rules the exam tests

Figures for tax year 2025, the year the 2026-27 SEE tests. Verify against the cited primary source.
Rule	What it says (2025)	Source
Assessment	3 years; early returns deemed filed on due date	IRC 6501(a), (b)(1)
Substantial omission	6 years: > 25% of gross income, or > $5,000 of foreign-asset income	IRC 6501(e)
Unlimited	Fraud, willful evasion, no return	IRC 6501(c)
Unfiled foreign info returns	Open until information furnished	IRC 6501(c)(8)
Extension	Form 872 (fixed) / 872-A (open); right to refuse or limit	IRC 6501(c)(4)
Collection (CSED)	10 years from assessment; suspended by OIC, IA request, CDP, bankruptcy, 6+ months abroad	IRC 6502, 6331(k)
Refund claim	Later of 3 years from filing or 2 years from payment; lookback limits	IRC 6511(a), (b)
Bad debt / worthless security	7 years	IRC 6511(d)(1)
Prompt assessment (decedents)	Form 4810: 18 months	IRC 6501(d)
Tax Court case	Assessment suspended while barred, + 60 days	IRC 6503(a)

Worked example

Facts: A taxpayer filed her 2021 return on time (April 18, 2022) showing $100,000 of gross income. She left off $30,000.

Result: $30,000 is 30% of reported gross income (> 25%), so the IRS has 6 years, until April 18, 2028, instead of April 18, 2025. Had she filed a fraudulent return, there would be no limit.

Exam traps

An early return starts the clock on the due date.
The 25% test compares the omission with gross income stated on the return.
Refund lookback limits how much you get back, not just whether you can file.
CSED suspensions add time; consents on Form 872 extend assessment only.