Once registered, you can claim back most of the GST/HST you pay on business purchases. Here’s how ITCs actually work and what you need to keep as evidence.
Last updated: June 2026
Once GST/HST-registered, you can claim an Input Tax Credit (ITC) for the GST/HST you paid on purchases and expenses used in your commercial activities — reducing the net amount you remit to the CRA. Your net tax owed is essentially (GST/HST you collected from customers) minus (ITCs on your eligible business purchases).
Generally, any GST/HST paid on goods or services used in your commercial (taxable) activities qualifies — office supplies, professional services, equipment, software subscriptions, and inventory. Purchases used for personal purposes, or for making exempt supplies (like most residential rent), generally don’t qualify, and mixed-use purchases require reasonable apportionment between business and personal or taxable and exempt use.
To claim an ITC, you need a valid supplier invoice or receipt showing the supplier’s GST/HST registration number, the amount of tax paid (or a statement it’s included), and enough detail to identify the purchase. Missing or incomplete documentation is one of the most common reasons ITC claims are denied on CRA review, so keeping organised records from day one matters.
Often yes, on certain capital property and other eligible purchases still held or used in the business at registration, subject to specific pre-registration ITC rules.
Yes, for claims above certain dollar thresholds, the supplier’s registration number is a required piece of documentation — missing this is a common reason for denied claims.
Only partially — meals and entertainment expenses are generally restricted to 50% ITC eligibility, similar to the income tax treatment of these costs.
You can generally only claim the ITC on the business-use portion, apportioned on a reasonable basis such as usage logs or square footage for home office costs.
Generally up to four years from the end of the reporting period in which the ITC could have first been claimed, though specific limitation periods can vary — don’t leave it too long.
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