Small Business Corporation

HST combines the 5% federal GST with a provincial component in five participating provinces. For 2026 the combined rates are 13% in Ontario, 15% in New Brunswick, Newfoundland and Labrador, and Prince Edward Island, and 14% in Nova Scotia since 1 April 2025. Elsewhere you charge the 5% GST alone, or GST plus a separate provincial tax. The rate follows the province of supply, not where your business sits.

A tax deduction is an amount subtracted from your income before tax is worked out, so it reduces the income being taxed rather than the tax bill directly. Its worth depends on your marginal rate: the higher the rate, the more the deduction saves. Common examples are RRSP contributions, child care costs, union dues, moving expenses and business expenses. Credits work the other way, reducing the tax calculated on that income.

You claim credits on your return, and they are applied against the tax already calculated on your taxable income. Non-refundable federal and provincial credits are each worked out by multiplying the eligible amount by the lowest rate for that jurisdiction, so the same claim is worth different money at each level. Unused amounts are lost at year end unless the particular credit allows a carry-forward or a transfer to a spouse. Refundable credits are paid whether or not tax is owing.

Tax liability is the total tax you owe for a period, worked out before any payments are credited against it. Subtract tax withheld at source and any instalments paid and you are left with the balance owing or the refund. In accounting terms it is a liability on the balance sheet until it is paid, which is why a corporation carries income tax payable, GST/HST collected and payroll source deductions as amounts held for the government.