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How GST works on sale prices in Canada

Published · 2 min read

Whether GST in Canada is charged before or after a discount, with a worked example and the difference in what the customer pays.

Key facts

PlaceCanada
TaxGST
Standard rate on file5%
Multiply net price by1.05
Tax share of a gross price4.76%
CurrencyCAD

Discount first, then tax

In general the discount reduces the taxable amount, and GST at 5% is charged on the reduced price. If a 15% discount is applied to a net price, the tax is calculated on the remaining 85%.

Worked example

Here is the calculation with sample figures. Change any number in the Canada Discount and GST Calculator to run your own.

Worked example: Canada Discount and GST Calculator
PriceCA$300.00
Discount (%)15%
Tax rate (%)5%
DiscountCA$45.00
Net amountCA$255.00
TaxCA$12.75
TotalCA$267.75

Does the order change the total?

Mathematically, applying a percentage discount and a percentage tax gives the same final price in either order. What changes is the tax amount you record and report, and that must reflect the price actually charged.

Vouchers and coupons

Store vouchers, manufacturer coupons and gift cards can each be treated differently. Some reduce the taxable price, others are treated as a form of payment. Check how each type is handled in Canada before you run a promotion.

Quick reference at 5%

Common amounts in Canada, worked both ways: adding tax to a net price, and extracting it from a price that already includes tax.

AmountTax on net amountGross (net + tax)Net if amount includes tax
CA$10.00CA$0.50CA$10.50CA$9.52
CA$50.00CA$2.50CA$52.50CA$47.62
CA$100.00CA$5.00CA$105.00CA$95.24
CA$250.00CA$12.50CA$262.50CA$238.10
CA$500.00CA$25.00CA$525.00CA$476.19
CA$1,000.00CA$50.00CA$1,050.00CA$952.38
CA$5,000.00CA$250.00CA$5,250.00CA$4,761.90

How Canada compares

Standard rates on file for other countries. A difference of a few points matters most on high-value purchases and on cross-border sales.

PlaceRate on fileCompared with 5%
Bulgaria20%higher
Cambodia10%higher
Cameroon19.25%higher
Chile19%higher
China13%higher
Colombia19%higher

Using the calculator step by step

  1. Open the Canada Discount and GST Calculator.
  2. Type your figures into the numbered lines. Results update as you type.
  3. Check the rate field. It starts at 5%; change it if a reduced rate, local surcharge or exemption applies to you.
  4. Read the result on the receipt panel, and use the formula shown under it if you need to explain the figure to a client or colleague.

Key terms

Withholding
Tax deducted at source, by an employer or payer, before the money reaches you.
Reduced rate
A lower rate that applies to specific categories, often essentials such as food, medicine or books.
Deduction
An amount subtracted from taxable income. It saves tax equal to the deduction times your marginal rate.
Gross amount
The amount after tax is added, which is usually what a consumer pays.
Marginal rate
The rate applied to the next unit of income. It decides how much of a raise or a deduction you keep.

Common mistakes to avoid

Run your own numbers. The Canada Discount and GST Calculator updates as you type and shows the formula it uses.

Frequently asked questions

Is GST calculated before or after a discount in Canada?

Usually after: tax applies to the discounted price the customer actually pays.

Does a discount reduce the GST I owe?

Yes, because the tax is a percentage of the reduced price.

This article is general information for planning, not tax advice. Rates and rules change; confirm with your tax authority or a qualified adviser.

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