Reverse British Columbia GST/PST Calculator

British Columbia stacks 5% federal GST on 7% provincial sales tax for a headline 12% — but the 7% PST is a retail tax with its own exemption list, and that list is what makes BC receipts genuinely hard to reverse. Four divisors cover most of what a BC wallet actually holds:

• 1.12 — general goods carrying both GST and PST.
• 1.05 — restaurant meals, most food, and other PST-exempt supplies, which carry the 5% GST alone.
• 1.15 — liquor, which carries a 10% PST rate rather than the general 7%.
• Nothing at all — zero-rated basic groceries and prescription drugs, where no tax was charged to extract.

Pick the wrong one and the error is not rounding: a $112.00 restaurant tab reversed at 1.12 reports $12.00 of tax when the receipt actually contained $5.33 — and the difference is money you would be claiming that you never paid.

This is the distinction that matters most in British Columbia: PST is not a value-added tax. A registered business recovers the 5% GST through input tax credits and eats the 7% PST as a cost. So on a BC receipt you are not reversing one tax — you are separating a recoverable tax from a non-recoverable one.

The arithmetic trips people because you cannot apply a GST tax fraction to a PST-bearing total. Take a $224.00 all-in equipment purchase. Divide by 1.12 to get the pre-tax base of $200.00. The GST slice is that base × 5% = $10.00, and the PST slice is the base × 7% = $14.00. Only the first figure goes on the GST/HST return. Applying 5/105 to the $224.00 total instead would produce $10.67 — an overclaim, because that total contains PST the fraction was never meant to see.

Two BC specifics change the base before you even start. Short-term accommodation can carry a Municipal and Regional District Tax of up to 3% on top of PST in participating municipalities, so a hotel folio is not a 1.12 calculation. And passenger vehicles priced above $150,000 attract a 15% PST rate on the relevant portion, which is why a luxury-vehicle bill of sale never reverses at the general divisor.

British Columbia is the only province to have adopted the HST and then unwound it. It harmonized in 2010 and, following a provincial referendum, returned to separate GST and PST on April 1, 2013. Receipts from that window carry a 12% harmonized tax that was fully recoverable; receipts since carry a 12% combination in which only the 5% federal slice is. The totals look identical and the claim is not — a genuine trap in any archive of older BC records.

Looking forward, BC has legislated a PST expansion to professional services — accounting, legal, and engineering — effective October 1, 2026. Invoices for those services dated before the change reverse at 1.05 (GST only); invoices dated after it will carry PST as well. For any firm reversing service invoices across that boundary, the invoice date, not the payment date, picks the divisor.

To back out the 12% sales tax from any British Columbia receipt or invoice, use the standard algebraic reverse formula:

For a total of $100.00 CAD:

• Total Paid: $100.00 CAD
• Pre-Tax Base: $100.00 ÷ 1.1200 = $89.29 CAD
• Total Tax Owed: $100.00 - $89.29 = $10.71 CAD

Breakdown: GST Portion (42% of tax): $4.46 CAD | PST Portion (58% of tax): $6.25 CAD