Canadians use the TFSA (Tax-Free Savings Account) to grow their savings for decades without the Canada Revenue Agency taking a cut.
But many investors assume that protection follows them across the border when they buy U.S. stocks. If you hold American dividend payers in a TFSA, there is a quiet cost buried in the fine print that catches many Canadian investors off guard.

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Why the IRS treats your TFSA differently
Under the tax treaty between Canada and the United States, the TFSA is not recognized as a registered retirement account. To American tax authorities, it looks like any other taxable brokerage account.
Notably, the IRS charges a 15% withholding tax on dividends paid by U.S. companies to non-residents. Since your TFSA does not count as a retirement account, every U.S. dividend you collect inside one gets clipped before it reaches your account.
Because the TFSA is tax-free in Canada, you cannot claim a foreign tax credit to get that money back. Before you start pulling every U.S. stock out of your TFSA, take a breath. The withholding tax only applies to dividends and is not levied on capital gains.
Basically, growth-focused companies that pay little or no dividends can still compound completely tax-free inside a TFSA. Think of names like Amazon, Alphabet, or smaller, fast-growing companies tied to the next wave of innovation in space, defence, and technology.
This is where a stock like Rocket Lab (NASDAQ:RKLB) comes into the conversation.
Why Rocket Lab fits the TFSA growth story
Rocket Lab does not pay a dividend, so the IRS withholding rule does not apply to investors holding it inside a TFSA.
On a recent investor conference call, Rocket Lab Chief Financial Officer Adam Spice laid out a business that looks far bigger than a small rocket launcher.
The company’s Electron rocket has now flown 88 times, with management expecting roughly 25–28 launches this year.
Spice said the fastest-growing segment, HASTE missions used for hypersonic testing, could grow 30% to 50% annually in the near term, while the rest of Electron’s business grows around 20% a year.
The bigger opportunity sits with Neutron, Rocket Lab’s larger reusable rocket expected to launch before the end of this year. Spice told investors that Neutron pricing runs around US$50–US$55 million per mission, and once the vehicle launches a couple of dozen times a year, it could add another US$1 billion in revenue at scale.
Rocket Lab has built out a full Space Systems division through a string of acquisitions, supplying satellite components like reaction wheels, solar actuators, and optical terminals. Spice noted that this segment already accounts for about 70% of revenue and recently helped the company secure a US$816 million contract with the Space Development Agency.
In my view, Rocket Lab is a high-conviction growth stock for investors comfortable with volatility. The combination of a maturing launch business and a vertically integrated satellite operation gives it multiple paths to scale.
I believe long-term investors who can stomach the swings that come with an early-stage space company stand to benefit meaningfully from holding it inside a TFSA, where every dollar of capital gain compounds without the CRA or the IRS taking a bite.
Rocket Lab is also projected to turn free cash flow positive in 2028. Analysts forecast FCF to expand from US$246 million in 2028 to US$1.2 billion in 2030.
Where to put your other U.S. stocks
You should consider owning U.S. growth stocks in the TFSA and dividend stocks in the RRSP (Registered Retirement Savings Plan).
The RRSP is recognized under the Canada-U.S. tax treaty as a retirement account. It means U.S. dividends held directly inside an RRSP avoid the 15% withholding tax entirely.
Understanding this small piece of fine print can meaningfully change how much of your money you can retain. Place your assets in the right account and let your TFSA do what it does best: compounding your growth completely tax-free for years to come.