Why moving a 401(k) to a RRSP isn’t always tax-neutral

For Canadians returning home after working in the U.S., few financial decisions feel as urgent as what to do with a former employer’s 401(k) account.

Canada’s tax rules appear, at first glance, accommodating. Paragraph 60(j) of the Income Tax Act allows a lump-sum withdrawal from a U.S. retirement plan to be contributed to an RRSP, offsetting the Canadian tax that would otherwise arise.

On paper, it looks seamless. In practice, it often isn’t.

Consider a returning Canadian with a $100,000 401(k) (all figures in U.S. dollars). To use the 60(j) provision, the individual must withdraw the funds and report the full gross amount as income in Canada.

Canadian tax is calculated on the Canadian-dollar equivalent of the gross withdrawal using the exchange rate in effect at the time of receipt. To neutralize the tax, the same gross amount must be contributed to an RRSP.

When a Canadian resident withdraws from a 401(k), the U.S. withholds tax at source. Under the Canada–U.S. tax treaty, that rate is generally 15% if proper documentation is filed. Without it, withholding can rise to 30%.

Assume treaty treatment applies. A $100,000 withdrawal results in $15,000 withheld and $85,000 deposited into the investor’s account.

Canada, however, taxes the full $100,000.

To avoid Canadian tax, the investor must contribute the entire $100,000 equivalent to an RRSP. This means an additional $15,000 must be sourced elsewhere to replace the amount withheld.

For households with ample liquidity, that may be manageable. For others, it introduces immediate cash-flow strain.

If only the net $85,000 is contributed, the remaining $15,000 becomes taxable in Canada. At higher marginal rates, that can translate into thousands of dollars of unexpected tax and the unused portion of the rollover cannot be deferred to a future year.

Age adds another layer of cost

Another area that often causes confusion is the 10% early-withdrawal tax that applies in the U.S. if the account holder is younger than 59½.

This amount is often described as a penalty, which leads people to assume it cannot be used as a foreign tax credit in Canada. However, Canada Revenue Agency technical interpretations have indicated that the additional tax under the U.S. Internal Revenue Code section 72(t) may qualify as a non-business income tax for foreign tax credit purposes when the withdrawal is included in Canadian income.

In other words, the 10% additional tax can potentially be eligible for a Canadian foreign tax credit, depending on the specific facts and how the withdrawal is reported.

Even when no early withdrawal penalty applies, foreign tax credits are not always perfectly aligned. Credits are limited to Canadian tax otherwise payable on the same income. Excess U.S. tax may not be fully usable, and refunds can take several months.

Add currency conversion, administrative processing and market timing risk during the transfer window, and what looked straightforward can become operationally messy.

None of this means a 60(j) rollover is inherently flawed. In some cases, particularly for retirees over 59½ with sufficient liquidity and moderate tax rates, it can work as intended.

But the provision is often described as a simple tax-free transfer. That characterization glosses over the cash mechanics and treaty nuances involved.

For many returning Canadians, alternatives such as leaving the 401(k) in place or rolling it into a traditional individual retirement account may offer greater flexibility without triggering immediate tax friction.

In cross-border planning, what appears tax-neutral on paper can become expensive in practice.