An online seller was charging one flat tax rate to every province. We corrected place-of-supply on thousands of orders and avoided a looming reassessment.
An e-commerce seller shipping across Canada charged its home-province rate to every customer, under- and over-collecting sales tax for two years. We recalculated the tax by destination under the place-of-supply rules, corrected the historical filings, and set up automated rate handling. The cleanup removed the exposure to a multi-province reassessment.
E-commerce sits across provincial sales tax regimes, marketplace collection rules and inventory held in other jurisdictions.
Registration is mandatory once taxable supplies pass $30,000 over four consecutive calendar quarters. Input tax credits require documentation that scales with invoice size.
Why it bites: Unmatched input tax credits are the first thing disallowed in a sales-tax review, and the assessment covers every period reviewed.
British Columbia, Saskatchewan and Manitoba run their own sales taxes alongside GST, filed separately, and unlike GST they are generally not recoverable as input credits.
Why it bites: Businesses expanding into a PST province routinely register late, and the province assesses from the date the obligation started, not the date of registration.
The rate charged follows the customer's province, not the seller's: 13% into Ontario, 15% into the Atlantic provinces, 5% plus provincial tax elsewhere.
Why it bites: A seller charging its own province's rate nationally is under-collecting on some sales and over-collecting on others, and owes the difference on the under-collected ones.
The CRA requires business records to be kept for six years from the end of the tax year they relate to, in a form that allows the return to be verified.
Why it bites: Where records cannot support the return, the CRA is entitled to assess on its own estimate — and the burden of disproving that estimate falls on the taxpayer.
Every engagement above was priced as a fixed fee agreed before the work started, and paid only once the client had reviewed the result. If any of this looks like your situation, the first step is a free 15-minute call — we will tell you plainly whether there is anything worth doing.
Reviewed for the 2025 tax year by Udit Gupta, Certified Tax Accountant. Figures describe a real engagement; outcomes depend on your own facts. Client details are omitted for confidentiality.
