If you take construction work on both sides of the Canada-US border, tax and compliance are where the two countries diverge most. The same job can be billed and documented very differently depending on whether it sits in Ontario or Ohio. This guide lays out the practical differences so you can set up your software and your paperwork correctly. It is a general overview, not tax advice — always confirm specifics with your accountant or a qualified advisor, because rates and rules change.
Sales tax: a fundamental difference
The biggest structural difference is how each country taxes sales. Canada has federal and provincial sales taxes that apply broadly. The United States has no national sales tax at all — it is set at the state level and often layered with local rates.
This means a single tax setting will never work for both countries. Your software needs to apply the right model per jurisdiction, and your invoices need to reflect it.
Canada: GST, HST, and PST
In Canada, the federal Goods and Services Tax (GST) applies across the country. Some provinces combine it with their provincial portion into a single Harmonized Sales Tax (HST), while others charge a separate Provincial Sales Tax (PST) on top of GST. A few jurisdictions apply GST only.
Which model applies, and the rate, depends on the province where the work is supplied. Construction services and materials are generally taxable, but the details and any rebates vary, so confirm with your accountant.
- GST: federal tax applied across Canada
- HST: combined federal and provincial tax in harmonized provinces
- PST: separate provincial tax charged alongside GST in some provinces
- The applicable model and rate depend on the province of supply
USA: state and local sales tax
In the United States, sales tax is governed by each state, and many states allow counties and cities to add their own rates on top. A handful of states have no statewide sales tax at all. Rules on whether construction labour and materials are taxable differ significantly from state to state.
In some states a contractor is treated as the end consumer of materials and pays tax at purchase; in others tax is charged to the client on the finished work. Because the variation is wide, the right setup depends entirely on the states you work in — verify the treatment for each one.
- No national sales tax; rules are set per state
- Local county and city taxes may apply on top of the state rate
- Whether labour and materials are taxable varies by state
- Some states tax the contractor at purchase, others tax the client on the job
Currency: CAD versus USD
Cross-border work means cross-border currency. A job in Canada should be quoted, invoiced, and reported in Canadian dollars, and a job in the US in US dollars. Mixing the two in a single report makes your numbers meaningless and complicates year-end filing.
Set currency per project or client, and keep CAD and USD totals separate in your financial reporting. If you convert between them, record the rate and date so your books stay defensible.
- Bill Canadian jobs in CAD and US jobs in USD
- Keep CAD and USD totals separate in reports
- Record conversion rates and dates if you move money across the border
Compliance documents in Canada
Beyond tax, each country expects different paperwork. In Canada, workers' compensation is administered provincially through boards such as the WCB or WorkSafe organizations. You are commonly expected to hold and provide clearance certificates and to track insurance certificates for subcontractors.
Keeping these organized per worker and subcontractor matters, because a missing clearance can hold up payment or expose you to liability. Confirm your specific obligations with the relevant provincial board.
- WCB / WorkSafe clearance certificates by province
- Insurance certificates tracked per subcontractor
- Provincial requirements that vary by jurisdiction
Compliance documents in the USA
In the United States, the paperwork looks different. Workers' Compensation insurance is typically required and regulated at the state level. When you hire subcontractors, you generally collect a W-9 form from each, and at year end you may need to issue 1099 forms to report payments. Workplace safety falls under OSHA, which sets recordkeeping and safety requirements.
As in Canada, your software does not have to file these for you, but it should give you a reliable place to store and track them so nothing is missing when it is needed. Verify your obligations with your accountant and the relevant agencies, since thresholds and rules change.
- Workers' Compensation insurance, regulated by state
- W-9 forms collected from subcontractors
- 1099 forms issued at year end where required
- OSHA safety and recordkeeping requirements
Setting it all up in your software
The practical takeaway is that cross-border contractors need software flexible enough to handle two tax systems, two currencies, and two sets of compliance documents without constant manual workarounds. Configure tax per jurisdiction, set currency per job, and keep a document store organized by worker, subcontractor, and project.
BuildersBridge supports Canadian GST/HST/PST and US state sales tax, lets you bill in CAD or USD, and provides document storage for clearances, Workers' Comp, W-9, and 1099 paperwork. It handles the mechanics so your filings are cleaner — but the responsibility for getting your specific tax treatment right always rests with you and your accountant.