Imagine opening your mailbox to find a letter from the CRA — not a refund notice, but a bill. A penalty, charged against your TFSA. The account with “tax-free” right there in the name.
It hit me the other day how many smart, careful Canadians are one innocent misunderstanding away from exactly that letter. The TFSA is the best wealth-building tool most of us will ever touch — but it has trip wires, and they are not marked with flashing lights.
A quick note before we go further: I am not a tax professional, and this is not tax advice. Think of this as a friendly heads-up from someone who has spent years watching good people learn these rules the expensive way. When in doubt, check your CRA My Account — and keep your own records, because the CRA’s numbers can lag behind real life.
First, the 30-second refresher
For 2026, the annual TFSA limit is $7,000. If you were 18 or older and a Canadian resident back in 2009 when the TFSA launched — and you have never contributed — your total lifetime room is now $109,000. Unused room carries forward forever, and anything you withdraw gets added back to your room on January 1 of the following year. Simple enough on paper. In practice, the devil lives in the details.
Mistake #1: Thinking your limit is $7,000
The $7,000 figure is the annual addition, not your personal limit. Your real limit is your own cumulative room: every year since you turned 18 (or 2009, whichever came later), minus everything you have ever contributed, plus withdrawals restored each January.
This is where people get burned. Maybe you opened TFSAs at two different banks and only tracked one of them. Maybe you trusted the number in CRA My Account without realizing it can lag months behind your actual activity. Let us do some quick Room Math: say your true room is $40,000, the CRA portal shows $47,000 because a recent contribution hasn’t been reported yet, and you contribute the full $47,000. That is a $7,000 over-contribution — and the meter starts running immediately.
Do this instead: run your numbers through a TFSA contribution room calculator and keep your own simple spreadsheet of every contribution and withdrawal. Your records are your best defence.
Mistake #2: Withdrawing and replacing the money in the same year
This is the single most common TFSA trap in Canada, and it catches people who did absolutely nothing shady.
Here is how it happens. You withdraw $10,000 from your TFSA in June for a home repair. In September, things are looking better, so you put the $10,000 back. Feels responsible, right? Wrong — that $10,000 of room does not come back until January 1 of next year. If you had no spare room, you have just over-contributed by $10,000.
And that brings us to the part nobody tells you at the bank…
Mistake #3: Underestimating the 1% monthly penalty
So what does the CRA do about excess contributions? It charges you 1% per month on the highest excess amount — every month it sits there. That is 12% a year, and it is not deductible. The CRA spells it out plainly on its excess-amounts page, and the notices usually land in late spring, long after the damage is done.
Let us run the numbers. That $10,000 you replaced in September? At 1% a month, that is $100 a month — $400 by year end, for money that was yours all along. A smaller $5,000 excess left alone for eight months still costs $400. These are not hypothetical numbers. This is real money, paid for the privilege of using your own savings.
The fix is boring and beautiful: remove any excess the moment you spot it, and never recontribute a withdrawal until the new year. Wealthsimple’s TFSA guide has a clean walkthrough of the withdrawal timing if you want a second source.
Mistake #4: Paying 15% tax inside your “tax-free” account
Here is the one that surprises even experienced investors. Your TFSA shields you from Canadian tax — but not from Uncle Sam. Dividends paid by US stocks and US-listed ETFs inside your TFSA get hit with a 15% US withholding tax, and unlike in a non-registered account, you cannot recover a cent of it.
Worked example: your US-listed ETF pays you $2,000 in dividends this year. $300 vanishes to withholding tax before it ever reaches you — inside the account with “tax-free” in its name. Over a decade of compounding, that drag is anything but small.
This is one reason I lean toward Canadian-listed funds for my TFSA — it is the same thinking behind my XEQT vs VDY breakdown: know what you hold, and know what it quietly costs you.
Mistake #5: Letting your TFSA nap in cash at 4%
And now the mistake that costs the most Canadians the most money — not through penalties, but through comfort. Millions of TFSAs are sitting in savings accounts earning 4% or less, while their owners believe they are “investing.”
As I wrote in The High-Yield Savings Trap, the danger is becoming so comfortable with 4% that you stop asking whether your money could be doing more. A TFSA stuffed with cash for 20 years is a sports car you only drive to the corner store.
To be clear: cash has its place. Your peace of mind fund belongs somewhere safe and boring. But long-term wealth inside a TFSA comes from growth assets — which is why starting to invest, even with small automatic amounts, beats waiting for the “right time.” I invest biweekly precisely so I never have to make that decision under pressure.
Your annual “Room Check” — do this instead
Let us wrap the fixes into one simple ritual. Once a year — January works beautifully — give your TFSA a Room Check:
- Log into CRA My Account and compare its room figure against your own contribution spreadsheet. Trust your records when they disagree.
- Confirm you have no withdrawals waiting to be recontributed before January 1.
- Check what your TFSA actually holds — and whether a 4% savings account is still the right home for long-term money.
- Automate this year’s contributions so the system does the work instead of your willpower.
Fifteen minutes, once a year. That is the entire price of never getting the scary letter.
The bottom line
The TFSA is a masterpiece of Canadian personal finance — flexible, powerful, genuinely tax-free when you respect its rules. But “tax-free” was never a synonym for “rule-free.” The penalties are real, the withholding tax is real, and the opportunity cost of a napping TFSA is the most real of all.
A TFSA doesn’t reward the clever. It rewards the careful. Do your annual Room Check, and let the account do what it was built to do.
And if taxes in general make your eyes glaze over, you are not alone — though as I have argued before, most people complaining about taxes are missing the bigger problem. And when tax season rolls around, filing your taxes is easier than it has ever been.