An online retailer faced a $75,000 GST/HST audit over mismatched input tax credits. We reconciled every transaction and reduced the liability to $3,500.
Outcome$71,500
SectorE-Commerce
AreaGST/HST
EngagementFixed fee, pay after service
What happened
A Canadian e-commerce business was audited over three years of GST/HST filings, with the CRA proposing a $75,000 reassessment based on mismatched input tax credits and shipping logs. We reconciled all invoices, matched shipping records to place-of-supply rules, and filed structured reconciliations. The reassessment dropped to $3,500.
E-commerce sits across provincial sales tax regimes, marketplace collection rules and inventory held in other jurisdictions.
The rules this turned on
GST/HST
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.
CRA audit and review
A review is won on documentation created at the time, not on explanations offered afterwards. The CRA asks for the source records behind a figure, and an unsupported claim is simply disallowed.
Why it bites: Most reassessments we reverse are not the result of a wrong position — they are the result of a correct position with no contemporaneous paper trail behind it.
Place-of-supply rules
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.
What this means for your business
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.
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