The time frame for amending a tax return depends on the tax authority and the country: United States (IRS):

• You can file an amended federal tax return to claim a refund within 3 years after the date you filed your original return or 2 years after the date you paid the tax, whichever is later

• If you did not file an original return, there is no time limit to file one, so you can file it late without needing to amend

• After these periods, you generally cannot claim a refund, but you may still file an amended return without refund rights.
• Special rules apply for cases of fraud or substantial underreporting, where the statute of limitations can be extended or removed entirely

Canada (Newfoundland and Labrador example):

• You can amend your income tax return up to 5 years after the fiscal year in which you received the assessment, even if you have a final assessment

Australia (ATO):

• For individuals, the time limit to amend an assessment is generally 2 years from the day after the notice of assessment is sent.
• For sole traders, the limit is 2 years for income years up to 2023–24, and 4 years for 2024–25 and later income years

• For small and medium businesses, the amendment period is 2 years for 2023–24 and earlier years, and 4 years for 2024–25 and later years

• Amendments outside these time limits may be allowed in exceptional circumstances such as fraud or evasion

United Kingdom:

• You have up to 12 months from January 31 following the end of the tax year to amend your return (e.g., for 2023/24 tax year, until January 31, 2026)

Summary Table

Country| Time Limit to Amend Tax Return for Refunds| Notes
---|---|---
USA (IRS)| 3 years from filing original return or 2 years from tax paid| No limit to file original return if none filed; exceptions for fraud
Canada| Up to 5 years after assessment received| Applies even after final assessment
Australia| 2 years (individuals), 2-4 years (sole traders/businesses)| From notice of assessment date
UK| 12 months from January 31 after tax year end| Applies to self-assessment returns

If you want to amend a tax return beyond these periods, you may need to file an objection or appeal, or in some cases, it may not be possible to amend at all

. In conclusion, the typical limit to amend a tax return for a refund is about 3 years in the US, 5 years in Canada, 2-4 years in Australia depending on taxpayer type, and 12 months in the UK. Always check the specific rules for your jurisdiction and situation.