Form RC1, Request for a Business Number, is the official application submitted to the Canada Revenue Agency (CRA) to obtain a Business Number (BN) and to register for one or more CRA program accounts. The Business Number is a unique 9-digit identifier assigned by CRA that serves as the single registration number for a business's dealings with the federal government. It is the Canadian equivalent of the U.S. Employer Identification Number (EIN) obtained through IRS Form SS-4, but is more comprehensive in that it links multiple program accounts under a single identifier.

The BN system was introduced by the federal government to simplify business interactions with CRA. Each BN can have up to four types of program accounts attached: GST/HST (identified by the RT suffix) for sales tax registration under Part IX of the Excise Tax Act (R.S.C., 1985, c. E-15); payroll deductions (RP) for employers who withhold income tax, CPP contributions, and EI premiums under the Income Tax Act (R.S.C., 1985, c. 1 (5th Supp.)) and the Canada Pension Plan Act (R.S.C., 1985, c. C-8); corporation income tax (RC) for corporations required to file T2 returns; and import/export (RM) for businesses importing or exporting goods under the Customs Act (R.S.C., 1985, c. 1 (2nd Supp.)).

The BN is also used as an identifier for provincial and territorial government programs. Several provinces have adopted the federal BN as their business identifier, creating a single business number that works across jurisdictions.

A Business Number is needed by any person or entity that carries on business in Canada or has tax obligations under federal legislation. Sole proprietors need a BN when they have employees (requiring payroll deductions) or when they are required to register for GST/HST because their taxable supplies exceed $30,000 in any single calendar quarter or in four consecutive calendar quarters. Partnerships require a BN for the same reasons — each partnership receives its own BN separate from the BNs of the individual partners.

Corporations incorporated under the Canada Business Corporations Act (R.S.C., 1985, c. C-44) or under provincial business corporations legislation receive a BN automatically upon incorporation from Corporations Canada or the provincial registry. However, they must still file Form RC1 if they need to add program accounts that were not automatically opened, such as payroll or import/export accounts.

New businesses should apply for a BN before they begin operations to ensure they can meet their filing obligations from the start. The BN is required before a business can remit payroll deductions, file GST/HST returns, file corporate income tax returns, or import goods into Canada. Application can be made online through CRA's Business Registration Online service, by telephone, by mail, or by fax using Form RC1.

The RC1 form requires complete identification of the business, including the legal name as it appears on the certificate of incorporation, partnership agreement, or provincial business name registration. The operating or trade name (DBA) must be provided if different from the legal name. The applicant must identify the type of business entity — sole proprietorship, partnership, corporation, trust, non-profit organization, or charity — as this determines the filing requirements and program account options.

For sole proprietorships and partnerships, the Social Insurance Number (SIN) of the owner or each partner must be provided. The SIN is a 9-digit number in XXX-XXX-XXX format assigned to Canadian residents for tax purposes, equivalent to the U.S. Social Security Number (SSN). CRA uses the SIN to link the business to the individual responsible for it. The SIN information is protected under the Privacy Act (R.S.C., 1985, c. P-21).

The application must include the physical business address and, if different, the mailing address. Contact information including a designated contact person, telephone number, and preferred language of correspondence (English or French, as guaranteed under the Official Languages Act) must be provided. The business activity description, NAICS code, main product or service, and expected annual revenue help CRA categorize the business and determine applicable filing requirements.

For each program account requested, additional information is required: GST/HST registration requires the effective date, fiscal year-end, proposed filing frequency, and estimated annual taxable supplies; payroll accounts require the expected number of employees, estimated annual payroll, and first pay date. All amounts must be stated in Canadian dollars (CAD).