Who is liable if we under-withheld on a payment to a non-resident?
The Canadian payer. Part XIII withholding is the payer's liability, not the recipient's, so an under-withheld amount is assessed against the business that made the payment rather than the supplier or shareholder who received it. Recovering it from the recipient afterwards is a commercial negotiation, not a tax remedy, and by then the money has usually left the country. That is why a withholding review protects the Canadian company first. It is looking for the payer's own exposure, and under-withholding you find in your own ledger is cheaper to fix than under-withholding an auditor finds for you.
Do we need documents on file before applying a treaty rate?
Yes. A review tests two things separately, the rate you applied and the eligibility documentation sitting behind it. A treaty rate is only defensible if the paperwork supporting the recipient's residence and entitlement was in hand when the payment was made, and is still current. We see reduced rates applied for years on a certification obtained once, at the start of the relationship, and never refreshed. On paper the rate looks right. On review there is nothing to support it, and the difference between the treaty rate and the statutory rate becomes the payer's liability.
Which payments should a withholding review actually look at?
Every recurring payment leaving the company to a non-resident, not only the ones already coded that way. The review starts from the payment side, meaning the ledger, the bank and the intercompany accounts, rather than from the slips already filed, because the payments that cause trouble are the ones nobody classified as cross-border in the first place. Management charges, licence fees, interest on a shareholder loan and rents are the usual finds. Once the population is mapped, each stream is tested against the treaty and against the documentation on file.
Our slips and our corporate schedules disagree, does that matter?
It matters, because both were filed and an auditor can read them side by side. Disagreement between the slips reporting payments to non-residents and the corporate schedules reporting the same amounts is one of the things a review looks for deliberately. Usually the cause is mundane. An accrual reversed in one place and not the other, a payment recorded gross in one system and net in another, or a stream reclassified part-way through the year. The point of finding it internally is that you can explain it in your own words, with the working papers beside it.
Is it worth reviewing withholding before the CRA asks about it?
That is the whole argument for doing it. Under-withholding found internally is cheaper than under-withholding assessed, because you choose the timing, you remit with a computation you have prepared, and you fix the process at the same time. Found by an auditor, the same error arrives with interest running and the documentation assembled under pressure, on the auditor's schedule rather than yours. A review also produces something durable, which is a written position on each payment stream. That is what the next person in the finance seat needs when the question comes back.
Our supplier says the treaty exempts them, can we stop withholding?
Not on the strength of the statement. The obligation is the payer's, so the payer needs the evidence, not the recipient's assurance. A review treats a claim like that as the start of the work. Identify the article the recipient is relying on, confirm it covers the type of payment actually being made, and get the residence and entitlement documentation on file before the rate is reduced. Where the documentation does not arrive, withholding at the statutory rate and letting the recipient claim relief from the other side is the safe course for the Canadian business.
How do I reduce withholding tax on a cross-border payment?
Before the payment, not after. Where a treaty gives a lower rate, the payer needs your residency declaration in hand to apply it; where the statutory rate would over-withhold on a gross amount, an advance application can authorise a reduced deduction on a net or estimated basis. Once the money has moved at the full rate, your remaining route is an elective return or a refund claim, which recovers the same cash far more slowly. See withholding refund and recovery.
What is OECD Pillar Two?
A global minimum effective tax for large multinational groups, delivered through top-up taxes rather than a single global rate. Where a group's effective rate in a jurisdiction falls below the agreed minimum, the shortfall is collected — by the parent jurisdiction under the income inclusion rule, by the source jurisdiction under a domestic top-up, or as a backstop by other jurisdictions. Canada has enacted implementing legislation. The compliance burden is data, long before it is tax. See BEPS and Pillar Two.
