TFSA Tax Trap 2026: 6 Ways Your TFSA Can Be Taxed

The TFSA tax trap is the handful of tax rules that turn a tax-free account into a taxable one. Most TFSA holders never run into them, and the tax applies whether or not the holder knew the rule existed. This guide lists every trap, what each one costs, and the CRA’s own worked examples, so you can check your own account against them. It is general education, not financial or tax advice.

YieldMaple checked the CRA’s TFSA pages and its TFSA guide (RC4466) on October 6, 2026: the over-contribution tax is still 1% per month for as long as the excess stays in the account, and the CRA’s examples below are copied from those pages.

TFSA tax traps at a glance

The six TFSA tax traps and what each one costs (checked October 6, 2026)

Feature	What it costs	Where it comes from
Over-contribution (excess amount)	1% per month for as long as the excess stays in the account (better on this row)	CRA, excess TFSA amounts page
Professional-style trading	The holder may have the account deregistered and the income taxed as business income	CRA, What is a TFSA page
US dividends	subject to US withholding tax of generally 15%, which cannot be recovered inside a TFSA (unlike in an RRSP, which the Canada–US tax treaty recognizes)	Wealthsimple TFSA FAQ; CRA TFSA guide
Same-year re-contribution	Treated as an excess, taxed at 1% per month	CRA, excess TFSA amounts page
Contribution while a non-resident	1% for each month the contribution stays in the account	CRA, non-resident TFSA page
Prohibited investment	50% of the investment's fair market value, plus an advantage tax of 100% of the income earned and capital gains realized on the prohibited investment	CRA TFSA guide (RC4466)

Sources: canada.ca TFSA pages and guide RC4466, and wealthsimple.com/en-ca/learn/tfsa-faqs, all checked October 6, 2026.

In plain sentences: an over-contribution costs 1% per month for as long as the excess stays in the account. Trading like a professional means the holder may have the account deregistered and the income taxed as business income. US dividends are subject to US withholding tax of generally 15%, which cannot be recovered inside a TFSA (unlike in an RRSP, which the Canada–US tax treaty recognizes). A same-year re-contribution without spare room is simply an excess, taxed at 1% per month. A contribution made as a non-resident is taxed 1% for each month the contribution stays in the account. A prohibited investment is taxed at 50% of the investment's fair market value, and the income and gains from it at 100% of the income earned and capital gains realized on the prohibited investment.

What is the TFSA over-contribution penalty?

The TFSA over-contribution penalty is a CRA tax of 1% per month on any excess amount, calculated on the highest excess amount in the account in each month for as long as the excess stays.

Three details make it more expensive than it first looks:

• Every month counts in full. If the excess comes out in the same month it went in, it is still taxed at 1% for that month. In the CRA’s example, $2,000 over-contributed in June and removed in September costs $20 a month for June, July, August and September, $80 in total.
• A partial withdrawal does not lower that month’s tax. The CRA’s second example: $6,000 over-contributed in August with $4,000 withdrawn in mid-September still costs $60 a month for both August and September, $120 in total. Then it charges $20 for October, when the remaining $2,000 excess is withdrawn that month.
• Deliberate excesses are taxed far harder. An over-contribution made on purpose may be taxed at the 100% advantage rate, which takes the income earned on the excess, not just a monthly slice.

Worked example (hypothetical numbers). Someone who had already used all their room withdraws $5,000 in March and puts it back in August of the same year, then notices and takes it out again in November. The excess is in the account for August, September, October and November, so the tax is $50 a month, or $200 in total, plus the time spent filing Form RC243. The same money put back on or after January 1 of the next year would have cost nothing, because the withdrawal is added back to room on January 1 of the next calendar year.

Trap 1: How does a TFSA over-contribution happen?

A TFSA over-contribution happens whenever total contributions go past your available room, and the CRA names three usual causes: miscalculating your available room, re-contributing a withdrawal in the same year without enough room, or contributing to several TFSAs without tracking the total.

The room figure itself is part of the problem. The CRA account shows TFSA room updated once a year, in the spring, with the previous year's transactions, because TFSA issuers report a year’s transactions by the end of February of the following year. A deposit made in, say, February can be missing from the number you see until the spring update of the following year. Your room is one total shared by all your TFSAs combined, and a bank or brokerage only sees its own account, not the TFSA you hold somewhere else.

The checks that catch it:

1. Take the CRA room figure, then subtract every contribution made this year at every institution, since the CRA figure may not include them yet.
2. Count each TFSA you hold, at every bank and brokerage, against the one shared limit.
3. Treat a withdrawal as unavailable room until on January 1 of the next calendar year.

The TFSA contribution limit guide shows the yearly limits ($7,000 for 2026) and how room builds up.

How do you fix a TFSA over-contribution?

You fix a TFSA over-contribution by withdrawing the full excess, then filing Form RC243 with Schedule A and paying the tax by June 30 of the year after the year the tax applies.

1. Withdraw the whole excess. Only a full withdrawal stops the tax after the current month, because the tax uses the highest excess in each month.
2. File the TFSA Return (Form RC243) and Schedule A (RC243-SCH-A). The CRA usually flags an excess typically in late spring, through your CRA account or by mail, but the filing obligation applies whether or not a notice arrives.
3. Ask for a waiver if it was an honest mistake. To ask, you send the CRA a letter explaining why the over-contribution happened and why it would be fair to waive or cancel the tax.

Trap 2: Can day trading in a TFSA be taxed as business income?

Yes. Per the CRA, TFSA holders who invest with the frequency and experience of a professional trader may have the account deregistered and the income taxed as business income.

The CRA does not publish a number of trades that crosses the line, and this page does not invent one. The CRA’s test is how the account is run as a whole: whether the holder trades with the frequency and experience of a professional. A TFSA that buys index ETFs and holds them for years is the opposite pattern. The consequence is large: income taxed as business income is no longer sheltered, which defeats the reason for using a TFSA.

Trap 3: Are US dividends taxed inside a TFSA?

Yes. US dividends paid into a TFSA are subject to US withholding tax of generally 15%, which cannot be recovered inside a TFSA (unlike in an RRSP, which the Canada–US tax treaty recognizes), per Wealthsimple’s TFSA FAQ checked October 6, 2026.

The CRA’s own TFSA guide says foreign dividends paid to a TFSA could be subject to foreign withholding tax, per the CRA's TFSA guide. The treaty rate for a Canadian-resident individual is 15%. The exemption in the Canada–US tax treaty covers pension and retirement plans, which are exempt from US tax, as long as the plan is operated exclusively to provide pension, retirement or employee benefits, and the US Treasury's technical explanation of the 2007 Protocol uses a Canadian RRSP as its example of a retirement arrangement described in that exemption. A TFSA is not treated that way.

What it means in dollars (hypothetical numbers): $50,000 of US stocks paying a 1.5% dividend yield pays $750 a year in dividends, and the US keeps $112.50 a year of it.

One correction to a common tip: holding a Canadian-listed ETF of US stocks (such as VFV instead of VOO) does not escape this tax inside a TFSA. The US tax is withheld from the dividends paid to the fund, before they reach you, and a TFSA cannot claim it back either way. The Canadian-listed version mainly changes the currency you trade in. The TFSA vs RRSP comparison covers which account the treaty exemption favours.

Trap 4: Can you re-contribute a TFSA withdrawal in the same year?

Only if you still have unused room: a withdrawal returns as contribution room on January 1 of the next calendar year, not on the day you take it out.

The CRA’s wording is that replacing a withdrawal is allowed only if you have available contribution room; the withdrawn amount itself comes back as room the next calendar year. So if your room was used up before the withdrawal, putting the money back in the same calendar year is an over-contribution, taxed at 1% per month until it comes out. This is one of the three causes the CRA lists by name, and the TFSA withdrawal rules guide walks through the timing month by month.

Trap 5: What happens to a TFSA when you become a non-resident?

Per the CRA, you can keep your existing TFSA, and income in it is not taxed in Canada (your new country may tax it), but new contributions are taxed and no new room builds up.

• New contributions are taxed. Any contribution made as a non-resident is taxed 1% for each month the contribution stays in the account, until you withdraw it or become a resident again.
• Going over your room at the same time stacks the tax. The CRA can impose two separate 1% monthly taxes.
• Room stops growing. You get no new room for any year you're a non-resident for the whole year (a part-year resident still gets that year's full dollar limit).
• Withdrawals abroad come back late. A withdrawal made while a non-resident is tax-free in Canada, but the amount cannot be re-contributed tax-free until you become a resident of Canada again.

US residents face an extra layer. The TFSA’s shelter is a Canadian rule. The CRA notes that income in the account may be taxed by your new country, and for people who become US tax residents, cross-border practitioners commonly point to US reporting on the account, including foreign-trust forms (3520 and 3520-A) and PFIC reporting (Form 8621) for Canadian funds held inside it. This page does not cover US filing rules; a cross-border tax professional can confirm which forms apply to a specific account.

Trap 6: What is a prohibited investment in a TFSA?

A prohibited investment is property the TFSA holder is closely connected to, and the CRA taxes it at 50% of the investment's fair market value.

Per the CRA’s TFSA guide (RC4466), that includes your own debt, and shares or debt of a corporation, trust or partnership in which you hold a significant interest, generally 10% or more (counting non-arm's-length holdings), or one you do not deal with at arm’s length. On top of the special tax, the holder owes an advantage tax of 100% of the income earned and capital gains realized on the prohibited investment. A separate rule covers non-qualified investments, taxed at 50% of the property's fair market value when it was acquired or became non-qualified. The CRA can refund the special tax in some cases where the investment is disposed of in time, but not when the holder knew or should have known it was prohibited.

The people this reaches are mostly owners of private companies, startup employees with founder shares, and investors in related-party deals. A TFSA holding the investments the CRA lists as generally permitted, cash, mutual funds, securities listed on a designated stock exchange, GICs, bonds and certain small business corporation shares, is not in this territory.

Checklist: the checks that catch each trap

1. Before each deposit: CRA room figure, minus this year’s contributions at every institution.
2. After a withdrawal: that amount is not room again until on January 1 of the next calendar year.
3. Trading style: frequent, short-term trading in a TFSA can be taxed as business income.
4. US holdings: US dividends are subject to US withholding tax of generally 15%, which cannot be recovered inside a TFSA (unlike in an RRSP, which the Canada–US tax treaty recognizes).
5. Before a move abroad: no tax-free contributions while a non-resident.
6. Private shares: holding a significant interest, generally 10% or more (counting non-arm's-length holdings) in a company makes its shares a prohibited investment.

For how the account works from the start, see the TFSA explained guide, and for where TFSA investing fits in a wider plan, how to invest in Canada.

Related TFSA guides

• TFSA contribution limit 2026: the yearly limits and total room
• TFSA withdrawal rules: how withdrawals affect room
• TFSA vs RRSP: what each account shelters
• How to invest in Canada: TFSA-first investing