Tax-Year vs Calendar-Year Deadlines
Tax-Year vs Calendar-Year Deadlines
The deadline to contribute to a tax-advantaged account depends on your country's tax year, not the calendar year. In the US, the IRA deadline is April 15. In the UK, the ISA deadline is April 5. Missing the deadline costs you a year of tax benefits.
Key takeaways
- US: April 15 following the tax year (e.g., April 15, 2025 for 2024 contributions)
- UK: April 5 of the tax year (e.g., April 5, 2025 for 2024–2025 tax year)
- Canada: June 15 following the tax year for RRSP contributions
- Australia: June 30 of the financial year (e.g., June 30, 2025 for 2024–2025 year)
- Missing a deadline means forfeiting a year of tax benefits and contribution room; it can't be recovered
US Tax Year: Calendar Year (January 1–December 31)
The US tax year is the calendar year: January 1 through December 31. Tax returns are filed by April 15 of the following year.
IRA and Roth IRA deadline: April 15 following the tax year.
- 2024 tax year: Contributions due by April 15, 2025
- 2025 tax year: Contributions due by April 15, 2026
You can contribute to either year's IRA in the window between December 31 and April 15. If you contribute $7,000 in February 2025, you can designate it as either a 2024 or 2025 contribution (your choice). Most brokers will default to the calendar year of the contribution (February 2025 = 2025 contribution), but you can contact them and request a different year.
401(k) deadline: December 31 of the tax year. Unlike IRAs, 401(k) contributions must happen through payroll within the calendar year. You cannot make catch-up contributions after December 31 for a given tax year.
HSA deadline: The same as IRA: April 15 following the tax year. However, most people make HSA contributions during the calendar year they're eligible, not after.
UK Tax Year: April 5–April 4
The UK tax year runs April 6 to April 5 (not January–December). This is a legacy system dating back centuries. Tax returns are filed by January 31 following the tax year.
ISA (Individual Savings Account) deadline: April 5 of the tax year.
- 2024–2025 tax year (April 6, 2024 to April 5, 2025): Contributions due by April 5, 2025
- 2025–2026 tax year (April 6, 2025 to April 5, 2026): Contributions due by April 5, 2026
The ISA limit resets every April 6. This means:
- If you contributed £15,000 to an ISA before April 6, 2024, that contribution is for the 2023–2024 tax year
- On April 6, 2024, your ISA allowance resets to £20,000 for the new 2024–2025 tax year
- You can contribute another £20,000 between April 6, 2024 and April 5, 2025
Many UK investors miss the April 5 deadline for the previous tax year while being eligible for contributions in the new tax year (after April 6), which can be confusing.
LISA (Lifetime ISA) deadline: Also April 5 of the tax year. Additionally, LISA contributions come with a government bonus of 25% (up to £1,000/year bonus on £4,000 contributions). The bonus is awarded in the tax year of contribution, so missing April 5 also means missing the government bonus for that year.
Premium Bonds: No contribution deadline (contributions are ongoing), but annual prize draws happen each month.
Canada: June 15 for RRSP, June 30 for TFSA
Canada's tax year is also the calendar year, but RRSP and TFSA deadlines differ.
RRSP (Registered Retirement Savings Plan) deadline: June 15 following the tax year.
- 2024 tax year: Contributions due by June 15, 2025
- 2025 tax year: Contributions due by June 15, 2026
The extended deadline (compared to April 15 in the US) is intentional: it allows time for tax return filing (which is March 6 in Canada) and gives people time to contribute based on their actual tax situation.
TFSA (Tax-Free Savings Account) deadline: December 31 of the tax year (same as US 401(k) rules). Unlike RRSP, TFSA contributions must happen within the calendar year.
RRSP contribution room: Canada's RRSP system uses "contribution room," which accumulates year-over-year. If you don't contribute the full amount you're eligible for in a given year, the unused amount carries forward indefinitely. This is different from the US (IRA room doesn't carry forward; if you don't contribute $7,000 in 2024, you lose that $7,000 forever).
This makes RRSP more forgiving: you can catch up on years you missed, as long as you have room.
Australia: June 30 for Superannuation, July 1 for Tax Year
Australia's financial year runs July 1–June 30 (opposite of the calendar). Tax returns are filed by October 31 following the financial year.
Concessional contribution deadline (superannuation contributions with tax deduction): June 30 of the financial year.
- 2024–2025 financial year (July 1, 2024 to June 30, 2025): Contributions due by June 30, 2025
Non-concessional contribution deadline (superannuation contributions without tax deduction): Same financial year, but you have until June 30 to catch up if you under-contributed in a previous year.
Personal tax filing deadline: October 31 following the financial year. This is significantly later than the US or UK, giving Australians more time.
Deadline Calendar: Side-by-Side Comparison
| Country | Tax Year | IRA/RRSP/Equiv Deadline | Financial Year End |
|---|---|---|---|
| US | Jan 1–Dec 31 | April 15 (next year) | Dec 31 |
| UK | April 6–April 5 | April 5 (same year) | April 5 |
| Canada | Jan 1–Dec 31 | June 15 (next year) | Dec 31 |
| Australia | July 1–June 30 | June 30 (same year) | June 30 |
Missing the Deadline: What Happens
If you miss the contribution deadline for a tax year, the consequences vary by account type and country.
US: IRA
- Deadline missed: You cannot contribute for that tax year. The $7,000 contribution room is lost forever.
- Excess contribution penalty: If you contribute after the deadline, it counts toward the next tax year (with potential excess contribution penalties if you've already maxed out next year).
- Correction option: If you realize mid-April (before filing your return) that you over-contributed or missed the deadline, you can file Form 5329 to report it and pay the penalty.
UK: ISA
- Deadline missed: You cannot contribute for that tax year. The £20,000 allowance (or £4,000 for LISA) is lost forever.
- Bonus forfeited: For LISA, missing April 5 also means forfeiting the government bonus (25% match, up to £1,000) for that year.
- Example: You contribute £4,000 to LISA on April 10, 2025 (after the April 5 deadline). The contribution counts toward next year's 2025–2026 allowance, not 2024–2025. You've missed the bonus for 2024–2025.
Canada: RRSP
- Deadline missed: Unlike the US, RRSP room carries forward. You can contribute in future years using accumulated room from prior years.
- No bonus lost: There's no government bonus (like UK LISA), so the consequence is just carrying forward the room.
Australia: Superannuation
- Deadline missed: Concessional (tax-deductible) contributions made after June 30 are treated as non-concessional, losing the tax deduction.
- Catch-up: You have until June 30 of the following year to make catch-up contributions under carry-forward rules (if you under-contributed in prior years).
Tax Deadline Workflow
Managing Multiple Tax Years (Expat Example)
If you live in one country but have investments in another (or you're an expat who just moved), you must track multiple tax years:
Example: US expat living in UK
- US: Must file Form 1040 reporting worldwide income by April 15 (the US doesn't recognize April 5)
- Can contribute to an IRA until April 15 (US deadline), even though they live in the UK
- UK: Must file Self-Assessment Tax Return by January 31 if self-employed or reporting foreign income
- Can contribute to an ISA until April 5 (UK deadline)
- Must track contributions to both accounts and ensure they don't create reporting issues
This requires separate accounting and reminder systems to ensure both deadlines are met.
Setting Reminders and Staying Organized
Given the variety of deadlines across countries and account types, setting reminders is critical:
For US investors:
- Calendar reminder: March 1 to "check IRA contribution status for current year"
- Deadline: April 15
For UK investors:
- Calendar reminder: March 1 to "check ISA/LISA contribution status for current year"
- Deadline: April 5 (earlier than most think!)
For Canadian investors:
- Calendar reminder: May 1 to "check RRSP contribution status for current year"
- Deadline: June 15
- Advantage: RRSP room carries forward, so catching up later is possible
For Australian investors:
- Calendar reminder: May 1 to "check superannuation contribution status for financial year"
- Deadline: June 30
- Post-deadline: October 31 for tax filing
Most tax software (TurboTax, Wealthsimple, ATO MyTax) will remind you of deadlines, but setting your own calendar reminders ensures you don't miss them due to software failure.
Coordination With Tax Returns
Contribution deadlines are separate from tax-filing deadlines:
- US: Contribute by April 15, file taxes by April 15 (same day, but they're independent)
- UK: Contribute by April 5, file Self-Assessment by January 31 following the tax year (different dates)
- Canada: Contribute by June 15, file taxes by June 15 (same day)
- Australia: Contribute by June 30, file taxes by October 31 (months apart)
The separation matters: You can contribute to an IRA on April 15 and then file your taxes on April 15 (with the contribution included). But if you file taxes before contributing, you'll need to file an amendment (Form 1040-X) to claim the contribution.
Next
Understanding contribution deadlines is the final piece of the funding puzzle. From linking your bank account to managing contributions across multiple countries and account types, the funding process is complete. The next chapter builds on this foundation by exploring how to use these accounts strategically to optimize your overall portfolio and tax situation.