Canada GST and HST invoicing rules: rates, credit notes and retention

Standard GST and HST rates

Canada does not have one national sales tax rate. The federal goods and services tax (GST) is 5% and applies across the country. Some provinces combine their provincial tax with GST into a single harmonized sales tax (HST). The Canada Revenue Agency (CRA) lists these combined rates:

• Ontario: 13% HST
• New Brunswick, Newfoundland and Labrador, and Prince Edward Island: 15% HST
• Nova Scotia: 14% HST, effective April 1, 2025

Alberta, the Northwest Territories, Nunavut, and Yukon charge 5% GST only. British Columbia (7%), Manitoba (7%), and Saskatchewan (6%) add a provincial sales tax on top of the 5% GST. Quebec adds 9.975% Quebec sales tax (QST), for a combined 14.975%.

The rate depends on the province or territory involved in the sale, so do not hardcode one rate. Store the customer's province or territory on each invoice and calculate tax from that field.

Registration threshold

You are a small supplier, and do not have to register, if your taxable revenue is $30,000 or less in any single calendar quarter and over the last four consecutive calendar quarters. Track revenue by calendar quarter and check the rolling four-quarter total at the end of each quarter, not only at year end. Once you go over the limit, the rules for charging and registering apply.

Credit notes and adjustments

When you reduce, refund, or credit GST or HST after a sale, the CRA says to issue a credit note to the customer that explains the adjustment. The customer may instead issue a debit note to you. If you adjust the tax, you can deduct the adjusted GST or HST in your net tax calculation. If you do not adjust, refund, or credit the tax, you do not need to change your net tax calculation.

Model each credit note as its own record that references the original invoice number. That lets you match each adjustment to the tax it reverses when you file.

Record retention

The CRA says you usually must keep records for 6 years from the end of the year to which they relate. The CRA may ask you to keep invoices longer. You must send a written request and wait for approval before you destroy records early.

Store electronic invoices in a form you can retrieve for the full six years.

Next step

Read the developer documentation to see how to model province-level rates and link each credit note to its original invoice.