An Ontario HST number is a federal CRA GST/HST program account, not a separate provincial HST number. The CRA’s registration page describes how to apply directly but did not state a specific account registration fee in the official material reviewed. Confirm any current account fee with the CRA; an optional intermediary’s charge is separate.
What are you registering?
The account normally consists of a nine-digit federal business number, the RT program identifier and a four-digit reference, for example 123456789 RT0001. A provincial business-name or incorporation registration is a separate process. Manitoba’s government FAQ states that obtaining a business number is free, but distinguishes the BN from fees that may apply to government program services. It does not establish a GST/HST account fee.
Apply through the CRA
- Decide whether registration is required or available voluntarily and identify the correct effective date.
- Gather your legal and operating names, structure, relevant owner or director details, fiscal year-end and estimated taxable sales.
- Sign in to a CRA account and use Business Registration Online (BRO) if eligible. Save or print the BN and RT account details during the session.
BRO cannot be used for every situation. If it does not apply to you, use the alternative in the CRA’s current registration guidance. An Ontario business registration or professional adviser may have its own separate charges.
When must an Ontario business register?
Most businesses use the $30,000 small-supplier tests for worldwide taxable supplies, including applicable supplies of associates. When one quarter exceeds the threshold, charge on the supply that crosses it; the effective date must be no later than that supply. When four consecutive quarters exceed it without a single-quarter excess, small-supplier status ends at the end of the following month; the effective date must be no later than the first supply after that point. In either case, apply within 29 days of the effective date. Taxi and commercial rideshare operators must register regardless of the threshold.
What happens after registration?
A registered seller charges the tax applicable to each taxable supply. For an ordinary taxable Ontario sale of $100 before tax, 13% HST is $13, for a $113 total. Other types or places of supply can have different treatment. Eligible input tax credits can reduce net tax, but require qualifying commercial use and supporting records. Returns and bookkeeping also continue after registration.
Related guides
Sources
Official guidance checked October 17, 2026.