From the Government of Canada

The Canada Revenue Agency (CRA) provides detailed guidance for businesses on when they are required to register for and charge GST/HST. It explains the thresholds, exemptions, and scenarios that determine your obligations, ensuring compliance with Canadian tax laws.

Generally, you will need to register for your Business Number (BN) before you can register for a GST/HST account.

You may register for a BN by using the online service at Business Registration Online (BRO). This is the quickest way to register for a BN. Once you have obtained your BN, you can then continue in the same session to register for a GST/HST account.

If you already have a BN and only need to register for a GST/HST account, you can Open or Manage an Account.

Disclaimer: For personalized advice and to ensure your business meets all requirements, consider consulting a professional accountant or the CRA directly.