TFSA Over-Contributions: What Happens and How to Fix a Mistake

A TFSA over-contribution penalty is one of the more avoidable mistakes in Canadian personal finance — and also one of the more common ones, almost always triggered by a specific, well-understood pattern rather than a wildly unreasonable contribution amount.

How the penalty actually works

This is a genuinely punitive, ongoing penalty, not a one-time fee. A $5,000 over-contribution left in place for 6 months accumulates a penalty of roughly $300 (1% × $5,000 × 6 months) — on top of potentially owing tax on any income the excess amount itself earned while sitting in the account.

The single most common cause: withdrawal-and-recontribution timing

The TFSA's biggest advantage — tax-free growth with full access to your money — is also the source of its most common tax trap.

This catches people specifically because it feels intuitively wrong — if you put $10,000 in, took it out, and are putting the same $10,000 back in, it can feel like your balance never should have changed. But the CRA's room calculation tracks contributions and withdrawals as separate events with different timing, not a net balance.

A worked example

Marcus has fully used his TFSA contribution room. In March, he withdraws $8,000 for a short-term need. In August, having resolved the need, he re-contributes the same $8,000 back into the account, assuming it's simply restoring what he took out.

• What actually happened: the $8,000 withdrawal doesn't add back to his contribution room until January 1 of the following year. His August re-contribution, made against zero available room, creates an $8,000 over-contribution.
• The penalty: 1% of $8,000 = $80/month, starting the month of the over-contribution and continuing until it's withdrawn. If Marcus doesn't catch the mistake until filing his taxes the following spring — roughly 7 months later — the accumulated penalty reaches $560, entirely avoidable if he'd simply waited until January to re-contribute.
• The fix: withdraw the excess $8,000 immediately upon discovering the mistake, which stops the penalty from accumulating further (though months already elapsed are still assessed).

Why your bank app's number isn't always reliable

This matters most for anyone holding TFSA accounts at more than one institution. Your contribution room is a single combined number across every TFSA you own — not a separate allowance per account — and no single bank's app has visibility into what you've contributed elsewhere. Someone with TFSAs at two banks has to manually track the combined total, or check CRA My Account directly, rather than trusting either bank's individual display.

How to fix an over-contribution

1. Withdraw the excess amount as soon as the mistake is discovered. The penalty is calculated on the highest excess balance during each month — earlier withdrawal limits further accumulation, even though months already elapsed are still assessed.
2. File Form RC243 (Tax-Free Savings Account Return) if required, reporting the over-contribution and calculating the penalty owed — the CRA may also identify the issue and assess it directly.
3. Consider requesting a waiver if the over-contribution was a genuine, reasonable mistake (such as the withdrawal-timing trap above) rather than a knowing excess contribution. The CRA has discretion to waive some or all of the penalty tax in these cases, though a waiver isn't automatic or guaranteed.
4. Check CRA My Account going forward before any contribution that approaches your known limit, rather than relying on a single institution's figure.

Common mistakes

• Assuming a withdrawal and a same-year re-contribution net out to zero. They don't — the withdrawal only restores room starting the following January 1.
• Trusting one bank's app as the full picture when TFSA accounts exist at more than one institution.
• Not checking CRA My Account before a contribution close to the known limit, especially after a recent withdrawal or a contribution made at another institution that may not be reflected yet.
• Delaying the fix after discovering an over-contribution. The penalty accrues monthly — the sooner the excess is withdrawn, the sooner the accumulation stops.

Sources

• Tax payable on TFSA excess TFSA amount — Canada Revenue Agency
• TFSA contribution room — Canada Revenue Agency

This article is for general educational purposes only and does not constitute financial or tax advice. TFSA rules and penalty calculations can change — confirm your specific contribution room through CRA My Account, and speak with a licensed financial professional before correcting an over-contribution or requesting a penalty waiver.

What to do next

For how the TFSA compares to the RRSP and FHSA when deciding where to prioritize contributions in the first place, see TFSA vs. RRSP vs. FHSA. If a first home purchase is part of the picture alongside TFSA savings, FHSA Explained covers the account with its own, different contribution-room mechanics.