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A Business Number, or (BN) is a unique, 9-digit number given by the Canada Revenue Agency to businesses and self-employed persons. The CRA uses the BN as a standard identifier for your business. Each BN is unique to a business or legal entity.
You need a Business Number (BN) if you are a Sole Proprietor or in a Partnership and you require what the CRA refers to as “Program Accounts”. Program accounts include GST/HST, Payroll, and Import/Export accounts.
You need a BN for your entity if your business is incorporated, and you might also need a business number to interact with other federal, provincial, and municipal governments in Canada.
Please see our TurboTax article of what is a Business Number? How do I Know if I Need One? to learn more about the Business number.
You can register for business number from the website of How to register for a business number or Canada Revenue Agency program accounts