MSP cross-border tax: US clients, vendor licensing, and hardware imports

Serving US clients without triggering US tax

An MSP whose technicians support American clients' networks remotely from Ontario generally has no US permanent establishment. So the Canada-US treaty protects that business income from US tax, even though the client is paying in USD. What the client's finance department needs is not silence but paperwork. That means a W-8BEN-E on file certifying your corporation's foreign status and treaty position, filed before the first invoice clears. Otherwise, the client's default withholding process may apply anyway. On the Canadian side, services supplied to a non-resident client are generally zero-rated for GST/HST. You still charge 0%, and register regardless, because those sales count toward the $30,000 threshold. You also keep claiming input tax credits on your Canadian costs.

The one pattern worth watching is a US client big enough that you start sending technicians on-site regularly rather than supporting them remotely. Occasional travel for a project kickoff is not a permanent establishment. A technician effectively stationed at a US client's office for months at a time starts to look like one. That conversation is worth having with us before the arrangement becomes routine, rather than after. Payroll withholding is a separate question again. A technician who is a Canadian resident working temporarily in the US does not automatically become a US taxpayer. But a longer posting can trigger state-level obligations independent of the federal treaty position. So we look at duration and state, before assuming a short-term assignment is tax-neutral.

Paying US vendors: usually simpler than it looks

Licensing and platform fees paid to US vendors are ordinary business expenses with no Canadian withholding involved. These include RMM and PSA platforms, and backup and security tools billed in USD. That is because Regulation 105 withholding applies to services a non-resident performs in Canada. It does not apply to a Canadian company paying a US vendor for software it uses here. Your MSP is GST/HST-registered and uses these licences entirely in a commercial activity. Because of that, the import self-assessment rules generally do not add extra HST on top of what you already remit. Those rules can apply when a Canadian business brings in a service or intangible from a non-resident. And ordinary purchased software licences used in your active business are excluded from T1135 reporting. That form targets foreign investment property, not the tools you run the business on.

Marketplace payouts flip the direction, and the withholding question is real

Publishing a tool or add-on through a vendor marketplace like Microsoft's flips the relationship. The marketplace operator is often a US entity paying you, not the other way around. That payout can look like US-source royalty income, subject to 30% withholding by default. A W-8BEN-E claiming the Canada-US treaty position is what gets that rate down. Computer software copyright royalties are among the categories the treaty generally exempts from source-country withholding entirely. But that only applies once the form is on file with the marketplace's payment processor, not after the first payout already had tax withheld.

Hardware imports: tariffs and origin on the gear you resell

Servers, switches, and firewalls sourced through a US-based distributor to fulfill a client build carry duty exposure. That exposure depends on where the equipment actually originates, not just where it shipped from. CUSMA preferential treatment applies only when the origin rules are met and documented. Tariff surcharges on certain electronics and network equipment have moved more than once in recent years. A fixed-price hardware quote signed months before delivery can quietly lose its margin if duty changes in between. We see MSPs handle this two ways. They either build a tariff-adjustment clause into hardware quotes, or hold pricing firm and treat the risk as a cost of winning the deal. Either is defensible, but it should be a decision, not something that happens by default. Keeping a paper trail of the distributor's country-of-origin documentation for each order is also worth the small effort. It is the first thing a customs review asks for, if a CUSMA preferential claim is ever questioned.