Cross-Border Stock Options and RSU Taxation: How Canada and the US Tax Your Equity Compensation

Equity compensation is common in technology, financial services, and multinational companies. Stock options and Restricted Stock Units (RSUs) that vest over multiple years create a cross-border problem when the employee worked in different countries during the vesting period. Both Canada and the US have rules for sourcing the income, and the two countries’ rules do not always produce the same split, which can lead to double taxation if the foreign tax credits are not coordinated.

How does Canada tax stock options?

Under ITA 7(1), a stock option benefit arises when the employee exercises the option (acquires the shares). The benefit is the difference between the fair market value (FMV) of the shares at the time of exercise and the exercise price (what the employee pays). This benefit is included in employment income for the year of exercise.

If the option meets the conditions for the ITA 110(1)(d) deduction (the exercise price was at least equal to the FMV of the shares at the date the option was granted, and the shares are common shares of a CCPC or a prescribed share of a public company), the employee can deduct 50% of the benefit. This effectively taxes the option benefit at the same rate as a capital gain.

For CCPCs specifically, ITA 7(1.1) defers the inclusion of the benefit until the employee disposes of the shares (not at the time of exercise). This deferral is unique to CCPC shares and does not apply to public company options.

How does Canada tax RSUs?

RSUs are taxed at vesting. When the RSU vests and the employee receives shares (or cash), the FMV of the shares at vesting is included in employment income. There is no 50% deduction for RSUs, because they do not meet the conditions in ITA 110(1)(d) (no exercise price was paid). The full vesting benefit is taxed as ordinary employment income.

The employee’s cost basis in the shares received is the FMV at vesting. Any subsequent gain or loss on selling the shares is a capital gain or loss.

How does the US tax stock options?

The US distinguishes between two types of stock options:

Non-Qualified Stock Options (NQSOs): Taxed at exercise as ordinary compensation income under IRC 83. The income is the spread between FMV at exercise and the exercise price. The employer withholds income tax and payroll tax on the spread. The employee’s basis in the shares is FMV at exercise.

Incentive Stock Options (ISOs): Under IRC 422, there is no regular income tax at exercise. The spread at exercise is an AMT preference item, potentially triggering Alternative Minimum Tax. When the employee sells the shares after holding for at least one year from exercise and two years from grant (qualifying disposition), the entire gain from the exercise price to the sale price is taxed as long-term capital gain. A disqualifying disposition (sale before the holding periods) converts part of the gain to ordinary income.

ISOs have a $100,000 annual limit: if the aggregate FMV of shares that become exercisable for the first time in any calendar year exceeds $100,000, the excess is treated as an NQSO.

How does the US tax RSUs?

RSUs are taxed at vesting as ordinary compensation income under IRC 83. The FMV of the shares at vesting is included in wages, and the employer withholds income tax and FICA. The employee’s basis is FMV at vesting. Subsequent gain or loss is capital gain or loss.

How is the income sourced between countries?

When an employee worked in both countries during the vesting period, the stock option or RSU income is sourced to each country based on the proportion of the vesting period that the employee worked in that country. Article XV of the US-Canada treaty allocates employment income to the country where the services were performed.

What about the 50% Canadian deduction on options?

The ITA 110(1)(d) deduction (50% of the stock option benefit) applies only to the portion of the benefit that is Canadian-source employment income. If 60% of the option benefit is Canadian-source and the option qualifies for the deduction, the employee deducts 50% of the 60% Canadian-source portion. The US-source portion is not eligible for the Canadian deduction (it is not Canadian employment income).

This matters because the Canadian deduction effectively reduces the Canadian tax rate on the option income to approximately 25% (half of the 50% top marginal rate). Without the deduction, the full benefit is taxed at up to 50%. For an employee who moved from Canada to the US and exercises options after departure, the Canadian-source portion (based on the vesting period worked in Canada) qualifies for the deduction, but only if the option meets the qualifying conditions.

What about ISOs held by a Canadian resident?

Canada does not have a concept equivalent to the ISO. If a Canadian resident holds ISOs from a US employer, Canada taxes the option benefit at exercise (under ITA 7(1)), regardless of whether the US defers the tax under the ISO rules. The 50% deduction under ITA 110(1)(d) may apply if the option meets the qualifying conditions (exercise price at or above FMV at grant, shares are prescribed shares).

This can create a timing mismatch: Canada taxes at exercise, the US defers to sale (for regular tax purposes; AMT applies at exercise). The employee may need to pay Canadian tax at exercise and wait until sale to realize the US tax benefit. The foreign tax credit may not absorb the Canadian tax in the year of exercise if the US regular tax is zero (though the AMT may generate some US tax liability).

Leaving Canada with unvested options or RSUs?

When a Canadian resident leaves Canada with unvested stock options or RSUs, the departure tax rules under ITA 128.1(4) do not apply to unvested options or RSUs. The deemed disposition applies only to property that the taxpayer owns at departure, and unvested options/RSUs are not yet property of the taxpayer (the employee has no right to the shares until vesting).

However, when the options vest or are exercised after departure, Canada retains the right to tax the Canadian-source portion of the benefit (the portion attributable to services performed in Canada during the vesting period). The former Canadian resident may need to file a Canadian return for the year of exercise/vesting to report the Canadian-source employment income, even though they are no longer a Canadian resident.

Canadian non-resident withholding applies to the Canadian-source portion. The employer (if Canadian) withholds tax under Regulation 102. If the employer is not Canadian, the former resident reports and pays the tax on a Canadian return.

What forms are involved?

Canadian side:

• T1 return: reports the employment benefit on line 10100 (employment income)
• T4 slip: the employer reports the option/RSU benefit in Box 14 and Box 38 (if the 110(1)(d) deduction applies, Box 39 or 41)
• NR4 slip: if the employer remits non-resident withholding on the Canadian-source portion paid to a non-resident
• Form T1212: deferral of option benefits (for CCPC shares)

US side:

• W-2: the employer reports the option/RSU income in Boxes 1 and 12 (Code V for NQSOs exercised)
• Form 1040: reports the income as wages
• Form 1116: claims the foreign tax credit for Canadian tax paid
• Form 6251: AMT calculation (for ISOs)
• Form 3921: ISO exercise report
• Form 3922: ESPP share transfer report

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.