EIN and Business Number

Glossary / EIN and Business Number · Also called Employer Identification Number, BN, Federal tax ID

How it works

In the US, you apply for an EIN free on the IRS website and, if approved, get it immediately. Websites that charge for an EIN are not the IRS. A sole proprietor with no employees can often use their Social Security number, but many get an EIN anyway to keep it off W-9s and invoices. Form an LLC or corporation with your state before applying.

In Canada, a business has one Business Number. Each program account adds a two-letter code and a four-digit reference to it: RT for GST/HST, RP for payroll deductions, RC for corporate income tax and RM for import-export. An unincorporated business needs a BN only when it registers for its first program account.

Worked example: What the numbers look like

A US EIN is written as two digits, a hyphen and seven digits, for example 12-3456789. It goes on Form 941, Form 940, W-2s and the W-9 you give your customers.

A Canadian BN with its accounts looks like 123456789 RT0001 for GST/HST and 123456789 RP0001 for payroll. A business with two payroll accounts, for example for two locations, would have RP0001 and RP0002. The RT number goes on every invoice where you charge GST/HST, because customers need it to claim input tax credits.

In AcboBooks

Company settings in AcboBooks have an EIN / Tax ID field for a US company and a Business Number field for a Canadian one, used on the payroll forms and slips.

Related terms

• Form 941
• W-2
• T4
• GST/HST
• 1099-NEC

Related on this site

• Tax calendar
• Tax forms
• Payroll guide

Sources

• IRS: Get an employer identification number
• CRA: When you need a business number or program account

Updated October 25, 2026. General information, not tax, legal or accounting advice. Rules and rates change; check with the IRS, the CRA, your state or province, or your accountant.

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