Introduction
A Canadian tech company that has been operating entirely with Canadian employees hits an inflection point when it hires its first US-based employee. What seems like a straightforward hiring decision creates a cascade of tax and compliance obligations on both sides of the border — obligations that, if not addressed in advance, can result in significant retroactive exposure.
Scenario: Brightfield Analytics Hires a Boston-Based Sales Director
Brightfield Analytics Inc. is a Toronto-based SaaS company. It has been operating for four years with eight Canadian employees. To accelerate US market penetration, it hires a Boston-based sales director, Sarah, who will work from home and travel to client sites across the US Northeast.
The founders assume that hiring Sarah is similar to hiring a Canadian employee — set up payroll, send cheques, issue a T4 at year end. This assumption is incorrect in almost every respect.
The Payroll Obligation
Sarah is a US-based employee. She is not subject to Canadian income tax on her US-source employment income (income earned in the US for services performed in the US). Her payroll obligations are US obligations:
US federal income tax withholding (IRS Form W-4)
State income tax withholding (Massachusetts state income tax)
US Social Security and Medicare (FICA) contributions — both employee and employer portions
Brightfield must register as an employer in the US — obtaining an Employer Identification Number (EIN) from the IRS and registering with the Massachusetts Department of Revenue — before issuing Sarah's first paycheque.
Issuing Sarah's pay as Canadian payroll and sending a T4 is incorrect. Sarah is not a Canadian employee and her income is not Canadian employment income.
The Permanent Establishment Risk
This is the most significant tax issue for a Canadian company with a US employee. If Sarah's activities in the US constitute a "permanent establishment" of Brightfield Analytics under the Canada-US Tax Convention, the company's US-source profits attributable to that PE become subject to US corporate income tax.
A US-based employee who is:
• Habitually exercising an authority to conclude contracts on behalf of the company
• Maintaining a stock of goods for the company
• Providing services that constitute an "agency PE"
...may create PE exposure for the Canadian corporation.
For a sales director who signs up US customers — even if formal contracts are executed in Canada — there is a genuine PE risk depending on the nature and extent of her authority. A US tax advisor should assess the PE position before Sarah's first day.
The Canadian Corporation's US Filing Obligation
If a PE exists, Brightfield must file US federal corporate income tax returns (Form 1120-F) and Massachusetts state tax returns, paying US corporate income tax on the profits attributable to the PE.
If no PE exists, there is no US corporate filing obligation — but the payroll registration and withholding obligations remain regardless.
The Canadian Tax Treatment
Sarah's salary is a deductible Canadian business expense for Brightfield. The corporate deduction is at the Canadian rate. The payroll mechanics are US obligations, but the income tax deductibility is Canadian.
Practical Steps Before Hiring Sarah
Obtain a US EIN from the IRS.
Register as an employer with Massachusetts.
Engage a US payroll provider (ADP, Gusto, Rippling — all support cross-border payroll).
Have a US tax advisor assess the PE exposure based on Sarah's specific role and authority.
If PE exposure exists, file the required US returns from the first year.
When to Speak With a CPA
A Canadian CPA with cross-border experience — or a collaboration between the Canadian CPA and a US CPA or tax attorney — should be engaged before the first US hire is made. The compliance obligations are straightforward once established; the retrospective correction if they are missed is far more complex.