Do we owe Canadian payroll tax for a short assignment here?
Very probably, yes. A foreign employer that sends staff into Canada owes Canadian payroll withholding on the Canadian workdays. It applies to the employer, not to the Canadian customer, and it applies even where the treaty will ultimately exempt the employee from Canadian tax on that income. That is the part that surprises people. The treaty answers whether the employee is taxable, and the withholding rules answer whether the employer must remit while that is being established. Relief from the withholding itself has to be arranged, by waiver or by employer certification, before the assignment rather than argued afterwards.
Our employee is treaty-exempt, why is withholding still required?
Because the two questions are separate. The treaty may well mean the employee owes no Canadian tax on the assignment. The payroll withholding obligation sits on the employer and arises from paying employment income for work done in Canada, whatever the eventual treaty outcome. Left alone, the employer withholds and remits, and the employee recovers by filing. The point of a waiver, or of certification for a qualifying non-resident employer, is to remove the withholding at the front end so neither of you spends the year waiting for a refund of tax that was never really due.
What is non-resident employer certification and who can use it?
It is the employer-level route. Instead of a waiver obtained for each employee on each assignment, a qualifying non-resident employer is certified and can then pay treaty-exempt employees for Canadian workdays without withholding, subject to the conditions of the certification and to tracking who worked where. It suits an employer with a recurring pattern of short Canadian assignments. A waiver suits a one-off project, or an employee who falls outside the certification conditions. Both are prospective. They are arranged before the assignment and cannot be applied to workdays that have already happened.
Can we get a regulation 102 waiver after the assignment has ended?
No. The waiver and the certification route are both prospective, arranged before the assignment rather than reconciled after it. Once employees have worked Canadian days and been paid without withholding, there is nothing left to waive. What exists is an unremitted employer obligation, and that is dealt with differently. Establish the workdays and the amounts, quantify what should have been withheld, and decide how to bring the position current. The employees may separately be entitled to treaty relief on their own Canadian filings, but that does not cure the employer's side of it.
Does the employer apply, or does each employee apply?
It depends which route you take, and it is worth settling early because it determines who does the work and when. A waiver is arranged for the employee and the particular assignment, so it needs the individual's details, the workdays and the treaty basis for exemption. Certification is arranged for the employer, and the employer then carries the ongoing obligation to track Canadian workdays and satisfy the conditions. Groups sending several people to the same project usually find the employer route less repetitive, provided they qualify for it in the first place.
We sent staff to Canada last year and withheld nothing, now what?
Start with facts rather than forms. Establish which employees had Canadian workdays, how many, what they were paid for those days, and whether the treaty would have exempted them. That gives you the size of the employer exposure, which is the thing the CRA would assess. From there the choices are about how to bring it current and what to put in place for the assignments already in the diary, since the waiver and certification routes only help prospectively. Doing this before an auditor raises it means the computation is yours and the explanation is yours.
How do I get back tax withheld in another country?
By the route that country provides, and it is rarely automatic. Where an elective return is available — on rent or pension income, for instance — filing it recomputes the tax on net income and refunds the difference. Where it is not, you file a refund claim with the withholding authority, supported by evidence of your residence and entitlement to the treaty rate. Both take time, which is why fixing the rate before payment is worth more. See withholding refund and recovery.
How do I claim a tax treaty benefit?
Three things usually have to line up: proof you are resident of the treaty country, a declaration to whoever is paying you so they withhold at the treaty rate rather than the statutory one, and the claim itself on the return of the country giving relief. Do it before the payment where a reduced rate is available — claimed afterwards it becomes a refund exercise instead, which takes far longer. See certificates of residency.