Tax assessment time limits by country decide how long you must keep records and how long an old mistake can come back. The three authorities have different clocks: a flat period that usually runs from filing in the U.S. and Canada, and a layered system in India that depends on the type of proceeding. For families with accounts abroad the clocks matter more than usual, because missing information returns can hold the door open in the U.S. and Canada for longer than the normal periods. This guide compares the limits for the IRS, the CRA and India's Income Tax Department and shows the dates for a sample return.
How do tax assessment time limits by country compare?
| Question | United States | Canada | India |
|---|---|---|---|
| Normal period | 3 years from filing (or due date if later) to assess additional tax | 3 years from the original notice of assessment (individuals, trusts, CCPCs); 4 years for others | Scrutiny notice within 3 months from the end of the financial year of filing; completion within 12 months from the end of the assessment year |
| Longer period | 6 years if more than 25% of gross income is omitted | Extended by 3 years for certain transactions with non-arm's-length non-residents and for foreign income issues | Reassessment notice within 3 or 5 years of the end of the assessment year, depending on the case |
| No limit | No return filed, or fraud | Misrepresentation through neglect, carelessness or wilful default, or fraud | Specific provisions apply; ask your Chartered Accountant |
| Foreign information | Form 8938 failure: open until 3 years after filing; foreign income omission above $5,000: 6 years; FBAR penalties: 6 years | T1135 late, missing or false: extra 3 years where foreign income was not reported | Foreign assets and Schedule FA fall under separate rules (including the Black Money Act); ask your CA |
| Refund or relief window | 3 years from filing or 2 from payment; 10 years for foreign tax credit | Taxpayer relief: 10 calendar years | Revised return before end of the assessment year; updated return later |
United States: how long can the IRS look back?
The IRS says the default period is 3 years, with 6 years when income you should have reported is more than 25% of the gross income on your return, and indefinitely if you do not file or file a fraudulent return. The Form 8938 instructions add two foreign-asset rules: if you fail to file Form 8938 or to report a specified foreign financial asset, the period for the year may stay open until 3 years after you file the form; and if you omit more than $5,000 of income relating to a specified foreign financial asset, the IRS has 6 years after you filed. The Form 3520 instructions say that, if the form is not complete by the due date, the assessment period for events it covers does not end before 3 years after the information is reported. For the FBAR, the statute (31 U.S.C. 5321(b)) lets the Treasury assess a civil penalty within 6 years from the date of the transaction, and a civil action to collect within 2 years of the assessment.
The IRS records page says to keep records for the period of limitations that applies to you. See IRS audit types.
Canada: what is the CRA reassessment period?
CRA states it can reassess tax returns for individuals, trusts and Canadian-controlled private corporations within three years from the original notice of assessment (four years for other taxpayers). The period is extended by three years in certain situations, including a transaction between a Canadian taxpayer and a non-arm's-length non-resident. The CRA's T1135 page says the period is extended by an additional three years if income from specified foreign property was not reported and the T1135 was not filed on time or has a false statement or omission. The CRA may also reassess at any time where there is a misrepresentation attributable to neglect, carelessness or wilful default, or fraud. Under taxpayer relief, a request can reach back ten calendar years. See CRA information requests and audits.
India: how long can the department examine or reopen?
The department's own table of limits (the Income-tax Act, 1961, as amended by the Finance Act, 2026, reviewed October 7, 2026) shows:
- Processing (summary assessment): within 9 months from the end of the financial year in which the return is furnished.
- Scrutiny: notice within 3 months from the end of the financial year in which the return is furnished; assessment within 12 months from the end of the assessment year in which the income was first assessable.
- Reassessment: a section 148A notice within 3 years, or 5 years, from the end of the relevant assessment year; the section 148 notice within 3 years 3 months or 5 years 3 months; completion within 12 months from the end of the financial year in which the reassessment notice was served.
- Updated returns: the 12-month assessment time counts from the end of the financial year in which the updated return is furnished.
The department's FAQ confirms that proceedings for assessment years up to 2026-27 continue under the 1961 Act even after April 1, 2026, and that the department can still reopen an earlier year such as AY 2023-24 in FY 2027-28 if the conditions are met. The reassessment chapter of the Income-tax Act, 2025 applies from tax year 2026-27, with completion due within one year from the end of the financial year in which the reopening notice is served. Your Chartered Accountant confirms the notice windows for tax years under the new Act. See scrutiny assessment in India.
Step by step: build your record clock
- List each return and filing by country and year.
- For each, note the filing date and the date of any assessment notice.
- Apply the longest period that fits: foreign-asset forms and omission rules extend the normal one.
- Keep supporting records until that date, and longer if a dispute is open. See record-keeping requirements by country.
- Keep copies of filings of foreign information returns, because they affect the clocks.
- Review the clocks whenever you amend; see amended returns by country.
Worked example
A family filed for 2022 as follows. U.S. return filed April 17, 2023: the normal 3-year window ends April 2026; if they omitted more than $5,000 of foreign-asset income, it runs to April 2029; if Form 8938 was never filed, it stays open until 3 years after the form is filed. Canada: a notice of assessment dated June 2023 gives a reassessment period to June 2026, extended to June 2029 if a late T1135 left foreign income unreported. India: return for assessment year 2023-24 filed in July 2023: scrutiny notice by June 30, 2024; scrutiny completed by March 31, 2025; a reopening notice (section 148A) within 3 years of March 31, 2024, that is by March 31, 2027 (5 years, March 31, 2029, in specified cases). All dates are hypothetical.
Mistakes to avoid
- Throwing away records after three years.
- Assuming a missing Form 8938, Form 3520 or T1135 only affects penalties. It can also extend the audit period.
- Forgetting that India can still reopen older years under the 1961 Act.
- Treating the same year as closed in all three countries.
- Filing amended returns without checking which clocks they affect.
How we can help
We help clients across Aurora and the Fox Valley review which U.S. clocks are open, respond to IRS inquiries, and file late international forms. We coordinate with your Canadian CPA and Indian Chartered Accountant, who handle CRA and Indian matters, so the file for each year is complete in all three countries. See our IRS and state tax representation and foreign account and asset reporting services. We cannot predict whether any authority will examine a return.
Frequently asked questions
How long should I keep tax records?
At least as long as the longest period that can apply. The IRS lists 3 years, 6 years, or indefinitely depending on the situation. Keep foreign records at least 6 years, and longer if a form is outstanding.
Does the clock start when I file or when the tax is due?
In the U.S. the 3-year period starts on the date you filed (or the due date if later). In Canada it starts from the original notice of assessment. In India the clocks run from the end of the financial or assessment year, depending on the step.
Is there a limit on FBAR penalties?
The statute lets the Treasury assess a civil penalty within 6 years of the violation.
Can India audit me after I move abroad?
Yes. The department's proceedings are based on the assessment year, not on where you live.
Can I stop the clock by amending?
No. An amended return does not end the assessment period. See amended returns by country.
Official sources
- IRS: How long should I keep records
- IRS Instructions for Form 8938
- 31 U.S.C. 5321, civil penalties (GovInfo)
- CRA: Transfer pricing, reassessment periods
- Income Tax Department of India: Time limit for issuing notices and completing assessments
- Income Tax Department of India: Reassessment proceedings FAQs
This page summarizes public guidance in plain language. If anything here differs from the official source, the official source controls.
General information only. It is not tax, legal, accounting or immigration advice for your situation, and rules change; confirm the current rules with the official source or a licensed professional in the relevant country.