How are RSUs and stock options taxed for cross-border workers?

Restricted Stock Units (RSUs) and stock options are among the most complex compensation elements for cross-border workers because they involve income that may have been earned over multiple years and in multiple countries. Both the US and your country of residence may claim taxing rights, and proper allocation is critical.

For RSUs, the general principle is that the compensation income recognized upon vesting should be allocated between the US and foreign country based on where you worked during the vesting period. If you received an RSU grant while working in the US and it vested after you moved to Canada, the income is typically split: the portion attributable to US workdays is US-source income, and the portion attributable to Canadian workdays is Canadian-source income.

The allocation formula is typically: (Workdays in Country X during vesting period / Total workdays during vesting period) x Total RSU income at vesting. Different countries may use different allocation methods, and tax treaties may override domestic rules.

Stock options add another layer of complexity because there are multiple tax events: grant, vesting, exercise, and sale. The US generally taxes the spread (difference between exercise price and fair market value) at exercise for Non-Qualified Stock Options (NQSOs), while Incentive Stock Options (ISOs) may receive preferential treatment. Foreign countries may tax at different events — some tax at grant, others at exercise, and others at sale.

Common challenges include: determining the correct sourcing method when you worked in multiple countries during the vesting/exercise period, avoiding double taxation when both countries claim the same income, dealing with different tax rates and timing of taxation, and properly claiming Foreign Tax Credits for taxes paid on allocated foreign-source stock compensation.

Many employers provide tax equalization programs for employees who relocate internationally, which can help manage the complexity. However, even with employer assistance, you need proper personal tax planning to ensure correct filing in all jurisdictions.