Business Registration with the CRA — Montreal CPA Firm Near You: Full 4-Page Guide to Business Numbers (BN), CRA Program Accounts, GST/HST, Payroll, Import/Export, and Compliance

Registering your business with the Canada Revenue Agency (CRA) is the first and most important step of operating legally in Canada. Whether you are starting a sole proprietorship, incorporating a company, hiring employees, selling online, registering for GST/HST, or importing/exporting goods, obtaining your Business Number (BN) and CRA program accounts is mandatory. Choosing the wrong registration path or delaying account setup can result in penalties, retroactive GST/HST assessments, payroll liabilities, missing refunds, and compliance problems.

This complete Mackisen CPA guide explains when you need a Business Number, how to register using Business Registration Online (BRO), how to retrieve an existing BN, how to add or close CRA program accounts, and how to maintain accurate CRA business information. Designed for new entrepreneurs, freelancers, contractors, corporations, and non-resident businesses entering Canada, this authoritative 4-page guide is optimized for high SEO value and strong client conversion.

Legal and Regulatory Framework

The CRA uses a Business Number (BN) as the universal identifier for businesses. A BN is a 9-digit number assigned to every business entity and is used to administer CRA program accounts. The BN does not replace provincial business registrations or incorporation numbers, but it is mandatory for federal tax compliance. CRA program accounts include GST/HST (RT), payroll deductions (RP), corporate income tax (RC), import/export (RM), and information returns (RZ). The BN format consists of a 9-digit number followed by a 2-letter program identifier and a 4-digit reference. For example, 123456789 RT 0001.

A Business Number is required when a business begins any taxable commercial activity, hires employees, exceeds the GST/HST small supplier threshold, imports or exports goods, files corporate income tax, or issues information slips. CRA regulations also require businesses to keep their account information up to date and to maintain accurate books and records for a minimum of six years. Beginning November 3, 2025, CRA will no longer accept registrations by phone; all registrations must be completed using Business Registration Online (BRO) or by an authorized representative such as Mackisen.

The CRA actively monitors unregistered commercial activity using credit card merchant reports, e-commerce platform disclosures, T4A and T5018 slip matching, GST/HST intelligence, and cross-border trade declarations. Businesses operating without proper registration can be reassessed, penalized, and subject to enforcement.

Key Court Decisions on Business Registration

Courts have issued several important rulings that directly affect business registration:

Courts have affirmed that business activity, not formal structure, determines registration requirements. Even if a business is not formally incorporated or registered provincially, CRA can require a BN if commercial activity exists.

Courts upheld that GST/HST obligations begin as soon as the $30,000 threshold is exceeded, regardless of bookkeeping delays. CRA can assess GST/HST retroactively if businesses fail to register on time.

Courts confirmed that workers paid as “contractors” might be classified as employees for tax purposes, requiring payroll accounts. Failure to register leads to back payments of CPP/EI plus penalties.

Courts ruled that personal services businesses (PSBs) must register properly and face higher tax rates and limited deductions if not structured correctly.

Courts determined that businesses must notify CRA of address, ownership, and structural changes. Failing to update CRA records invalidates correspondence and may escalate compliance action.

These decisions reinforce the need for proper CRA registration, correct program accounts, and accurate business information.

Why CRA Targets Business Registration

The CRA prioritizes business registration compliance because unregistered activity often correlates with under-reported income, missing GST/HST, unpaid payroll deductions, and late corporate filings. CRA uses advanced data-matching tools to detect commercial activity, such as merchant credit card data, online business platform records, GST/HST cross-matching, contractor reporting in the construction industry, and foreign trade data. Industries most frequently targeted for registration compliance include construction, trucking, restaurants, retail, hospitality, daycare, e-commerce, professional services, consulting, gyms, salons, and non-resident sellers.

CRA enforces registration rules to ensure GST/HST is collected, payroll deductions are remitted, corporate returns are filed, and import/export activity is properly monitored. Businesses operating without a Business Number risk reassessments, penalties, garnished refunds, or frozen accounts.

Mackisen Strategy

Mackisen CPA Montreal ensures that every business is registered correctly, supported, and compliant. We help clients determine whether they need a BN, GST/HST account, payroll account, corporate tax account, or import/export account. We register businesses through Business Registration Online (BRO) and ensure the account structure matches the business model. We retrieve or merge existing BNs, prevent duplicate registrations, update CRA records for address or ownership changes, and handle closures of accounts that are no longer needed.

Our corporate clients rely on us to manage GST/HST compliance, payroll setup, corporate tax obligations, and import/export requirements. Mackisen ensures accurate program account setup, ongoing monitoring, CRA correspondence management, integration with accounting software, and expert response to CRA compliance letters. Our clients avoid penalties and begin operations with a clean, fully compliant tax foundation.

Real Client Experience

A self-employed contractor exceeded the GST/HST threshold but never registered. CRA retroactively assessed thousands in GST/HST. Mackisen completed a voluntary disclosure, registered the account, and recovered significant penalties.

A startup corporation began paying employees without opening a payroll account. CRA assessed unpaid CPP and EI premiums plus penalties. Mackisen registered the payroll account, corrected remittances, and negotiated a payment plan.

A non-resident Amazon seller entered the Canadian market without GST/HST or import/export accounts. CRA flagged their activity. Mackisen registered their BN, GST/HST, and RM accounts, allowing them to operate legally.

A business owner operated under multiple trade names and did not realize they already had a BN. CRA flagged duplicate registrations. Mackisen consolidated the accounts and corrected the business profile.

When You Need a Business Number (BN)

You need a Business Number when you begin commercial activity. Situations requiring a BN include operating as a sole proprietor with commercial income, incorporating a business, collecting GST/HST, exceeding $30,000 in taxable revenue, hiring employees, opening payroll accounts, issuing T4/T4A slips, importing or exporting goods, operating an e-commerce or online business, or managing a corporation.

Even if your revenue is below the GST/HST threshold, voluntary registration may be beneficial to claim input tax credits (ITCs). Contractors, consultants, freelancers, and online sellers benefit from registering early.

Register for a BN and CRA Program Accounts

You may register online using Business Registration Online (BRO), through CRA’s Represent a Client portal if you authorize Mackisen, or through provincial business registries that integrate with CRA systems. After November 3, 2025, phone registration will no longer be accepted.

Program accounts include the RT GST/HST account, RP payroll account, RC corporate tax account, RM import/export account, and RZ information return accounts. Each account serves a specific purpose, and registering the wrong account can cause misfiled returns, penalties, or delayed processing. Mackisen ensures your accounts are correct from the start.

Ways to Find an Existing BN

If you do not know your BN, you can find it through CRA My Business Account, previous CRA letters, corporate documents, provincial registries, or by authorizing Mackisen to retrieve it securely. Businesses often lose track of BNs due to old corporations, dissolved entities, trade name confusion, or incomplete past filings. We help locate or consolidate BNs to avoid conflicts.

Maintaining Your Business Information

Businesses must notify CRA of changes to ownership, business address, directors, banking information, fiscal year-end, program accounts, or closure of operations. Failure to update CRA can result in misapplied payments, missing correspondence, frozen refunds, or compliance action. Mackisen maintains your CRA business profile to ensure accuracy and prevent problems.

Common Questions

Do I need a BN if I am just freelancing?
Yes, if you need GST/HST, payroll, or information return accounts.

Can one person have multiple BNs?
No. One BN per business entity, but multiple program accounts under it.

What if I never registered but earned business income?
You must register retroactively and may owe penalties, which Mackisen can help reduce.

Is GST/HST automatic when I get a BN?
No. You must register the RT account separately.

Why Mackisen

With over 35 years of combined CPA experience, Mackisen CPA Montreal ensures your business registration with CRA is correct, efficient, and compliant. Whether you are starting your first business, expanding operations, hiring staff, selling online, or entering the Canadian market as a non-resident, Mackisen provides expert registration, setup, and compliance support. Our team protects your business, prevents CRA penalties, and sets you up for long-term success.

If you want expert guidance registering your business, opening CRA program accounts, or managing CRA compliance, Mackisen ensures your business starts strong and stays protected.