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Handling tax treaties in Canadian accounting mostly means keeping proof. Who got paid, where they live, and why you withheld less than the default 25%. If a non-resident won’t certify their status, the CRA says the payer withholds the full statutory rate.
What should be on file before you pay a non-resident?
A signed certification. The CRA has three forms for it. NR301 is for non-resident individuals and trustees, NR302 for partnerships with non-resident partners, and NR303 for hybrid entities that count as corporations or trusts in Canada. Each one certifies beneficial ownership, residency and eligibility for treaty benefits.
Collecting them isn’t mandatory. The CRA says so plainly:
Completing Form NR301 is not mandatory.
More information on forms NR301, NR302, and NR303, Canada Revenue Agency, canada.ca
It does recommend them, and it’s easy to see why: without one, you have nothing to show for the lower rate. A certificate of residency from the other country’s tax authority may also be required to get treaty benefits.
What happens if the form never comes back?
You withhold at 25% and remit it. The non-resident can ask for the difference later on Form NR7-R. That’s their job, not yours, but it does mean the money sits with the CRA for a while and your payee may be unhappy.
The risk runs the other way too. A payer who applies a reduced rate without proper documentation can be assessed, with penalties and interest. So when in doubt, withhold the full amount. Refunding is cheaper than explaining.
| Situation | What you withhold | What to keep |
|---|---|---|
| Certification received, treaty rate applies | The treaty rate | Signed NR301, NR302 or NR303, residency proof |
| Non-resident refuses to certify | 25% | A note of the request and the refusal |
| No information at all | 25% | Payment record and NR4 slip |
| Payee wants money back later | 25% stays remitted | Their NR7-R request |
How much does a treaty rate change the books?
Say the company pays a $10,000 dividend to a non-resident shareholder. At 25% you withhold and remit $2,500, and the shareholder receives $7,500. If a treaty allowed 15% (an illustration, since rates differ by treaty and by payment type), you’d withhold $1,500 and they’d receive $8,500. Same payment, $1,000 apart.
For comparison, a resident of Ontario with no other income who receives $10,000 of other dividends pays $2,027.86 of extra tax in the dividend tax calculator. The two systems don’t line up, so don’t use one to check the other.
Where do treaty facts belong in your records?
Give each non-resident payee their own file, whatever software holds it. Put in the form, the date received, the country, the type of payment and the rate you applied. Keep it with the NR4 slip, which is how you report amounts paid to non-residents.
Then add a yearly check. Have residency or ownership changed? A form signed in 2023 doesn’t tell you where someone lives in 2026. For the draft versions of these forms, the CRA says a completed form expires when eligibility or the withholding rate changes, or three years after it was signed, whichever comes first. The same page says to keep the forms for six years from the end of the last tax year they relate to. Ask the payee to reconfirm whenever anything shifts, and don’t let a three-year-old signature sit there unchecked.
What about foreign tax you paid yourself?
That’s the mirror image, and it lives on your own return. A corporation that pays tax abroad on business income claims the federal foreign business income tax credit on Schedule 21, one country at a time. Keep the foreign tax receipts sorted by country and year so the schedule is quick to fill.
To see what the corporation owes before any credit, use the corporate tax calculator. On $100,000 in Ontario it shows $11,696, based on a blended 2026 small business rate that isn’t published as one figure, so treat it as an estimate. If you or an owner also earn abroad, the income tax calculator covers only Canadian tax.
Common mistakes with treaties
Assuming the rate from a friend’s treaty applies to yours is the classic. Assuming a treaty covers every kind of payment is another, since the CRA describes reductions for interest, dividends and royalties in particular. And applying a treaty rate on a phone call, with nothing in writing.
Picture a small software firm in Waterloo paying a contractor abroad. The accountant asks “do we have the form?” and the answer is “he said it’s fine”. That’s the sentence that turns into a reassessment. A one-page signed form takes a few minutes to get while the invoice is still fresh.
No individual treaty was read for this page. The text of each is on the Finance Canada site, and the country’s own tax authority explains what it needs from its residents.
What this page is based on
The 25% default, the form descriptions and the NR7-R route come from the CRA page on forms NR301, NR302 and NR303, read in 2026. The treaty summary is from the CRA tax treaties page. Calculator figures use 2026 data and, for Ontario dividends, credit rates that haven’t been checked against a 2026 form.
Frequently asked questions
Is form NR301 mandatory?
No, the CRA says completing it isn't mandatory, but it recommends collecting NR301, NR302 or NR303 as proof for a treaty rate.
What do I withhold if the payee won't certify?
The full statutory rate, which is 25%.
Can a non-resident get money back later?
Yes, the CRA points to Form NR7-R for a refund request.
What is the risk of applying a treaty rate without paperwork?
The CRA says you can be assessed, with penalties and interest.
Do I need a certificate of residency?
The CRA says one may be required to get treaty benefits, so ask your payee for it.
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