How to Include Your CRA Business Number on Invoices

What Is a CRA Business Number?

The CRA Business Number (BN) is a 9-digit identifier assigned to your business when you register for any CRA program — GST/HST, payroll, corporate income tax, or import/export accounts. Think of it as the federal equivalent of a SIN, but for your business rather than you personally. One BN can be associated with multiple program accounts, each identified by a two-letter code and a four-digit sequence number.

The program accounts most relevant to freelancers and contractors are:

• RT — GST/HST account (RT0001 is the first GST/HST account under your BN)
• RP — Payroll deductions account (only needed if you have employees)
• RC — Corporate income tax account (only if you incorporate)

As a sole proprietor or unincorporated freelancer, your primary account is almost always the GST/HST account: 123456789 RT0001. The 9-digit BN (123456789) is your root business identifier; RT0001 is the specific program account suffix identifying it as a GST/HST return account.

When you see "GST/HST Number" or "Business Number" on an invoice, both refer to the same thing: your BN followed by the RT0001 program account identifier.

When Your Business Number Is Required on an Invoice

The CRA has tiered requirements for what information must appear on a commercial invoice, based on the total amount charged. These rules apply to invoices that include GST/HST. The rules are found in the Excise Tax Act and CRA's GST/HST memoranda series.

In practice, almost every freelance invoice exceeds $150. A single hour of professional services at any reasonable rate crosses the threshold. The rule is not especially onerous — you simply add your BN to your invoice template once, and it appears on every invoice automatically.

How to Format Your GST/HST Number on an Invoice

The CRA does not mandate a specific placement on the invoice, but it must be clearly visible and identifiable. Here are the accepted conventions:

Correct Format

Your GST/HST number should be displayed as:

• GST/HST #: 123456789 RT0001
• GST Registration: 123456789 RT0001
• Business Number: 123456789 RT0001
• GST No. 123456789 RT0001

All of these are acceptable. The label "GST/HST #" is the most widely understood. The key requirement is that the BN and RT0001 suffix are present and unambiguous.

Where to Place It on Your Invoice

Two common placements work equally well:

1. In the supplier information block — directly below your business name, address, and email at the top of the invoice. This is the cleanest approach and mirrors how incorporated businesses present their registration numbers.
2. Adjacent to the tax line item — in the totals section, next to the "HST (13%)" or "GST (5%)" line. This directly associates your registration number with the specific tax being charged, which is useful for clients reconciling their ITC claims.

Example of a supplier block with the BN included:

Why Your Clients Care About Your Business Number

This is the most overlooked aspect of the BN requirement, and it affects your client relationships directly. When a business client pays your invoice, the HST or GST they paid to you is an expense to them — but they can recover it through an Input Tax Credit (ITC) on their own GST/HST return. This recovery is only possible if your invoice meets CRA requirements, including showing your BN on invoices over $150.

If your BN is missing from an invoice over $150:

• Your client cannot claim the ITC for the tax they paid you
• For a $5,000 invoice with $650 in Ontario HST, your client loses $650 they could have recovered
• If the CRA audits your client's ITC claims, that specific claim will be disallowed and your client will owe the $650 back to the CRA — plus interest
• Your client may ask you to re-issue the invoice with your BN, which creates administrative back-and-forth

In a B2B context (which is the majority of freelancing), getting your BN on invoices is not just a personal compliance matter — it is a service to your clients. Corporate clients, in particular, often have accounts payable processes that check for supplier registration numbers before approving payment. Missing a BN can delay payment.

What If You Haven't Registered Yet?

If your revenues are under the $30,000 small supplier threshold and you have not yet registered for GST/HST, you should not charge GST/HST on your invoices, and you have no BN to display. This is fine and legal — you simply issue invoices without any tax component.

To make your status clear to clients (especially corporate clients who may query the missing tax), you can add a note to your invoice such as:

"No GST/HST charged — supplier qualifies as a small supplier under the Excise Tax Act (revenues under $30,000)."

This one line prevents confusion and tells your client they cannot claim an ITC (because no tax was charged) and that there is no missing BN to track down. It also demonstrates you understand the rules, which builds confidence.

What NOT to Do

• Never charge GST/HST without a registration number. Collecting tax you are not authorized to collect is a serious compliance violation. The CRA treats this as unremitted tax owing, and you can be assessed for amounts you collected without registration.
• Never put your Social Insurance Number (SIN) on an invoice. SINs are personal identifiers used for employment and benefit purposes. They should never appear on business invoices. If someone asks for your "tax number," they want your Business Number — not your SIN.
• Never fabricate or guess at a BN. If your registration is pending and you are awaiting your BN from the CRA, wait until it arrives before issuing invoices that include GST/HST.

Common Business Number Mistakes

1. Wrong Format — Missing the RT0001 Suffix

Displaying only the 9-digit BN (e.g., "123456789") without the program account identifier (RT0001) is technically incomplete. A BN without the program account suffix does not specifically identify it as a GST/HST registration. Always write the full identifier: 123456789 RT0001.

2. Using the Wrong Program Account

If you have both a GST/HST account (RT0001) and a corporate income tax account (RC0001) under the same BN, make sure you are displaying the RT account, not the RC account. On a GST/HST invoice, only the RT0001 suffix is relevant. Displaying RC0001 is confusing and technically incorrect.

3. Registering Late and Backdating Invoices

If you exceeded the $30,000 threshold in October but only registered in December, you cannot go back and retroactively add your BN to all the October–November invoices and charge GST/HST. Those invoices were issued without registration. The correction process involves contacting the CRA, not altering already-issued invoices. Backdating registered invoices is an audit risk.

4. Displaying an Expired or Cancelled Registration

If you close your business or voluntarily deregister from GST/HST but continue to invoice clients with your old BN, you are displaying a cancelled registration number. Clients who verify through the CRA GST/HST Registry will see the registration is inactive, which creates compliance concerns for their ITC claims. Keep your registration current for as long as you are invoicing for taxable supplies.

5. One Business, Two Registrations

Some freelancers who operate under both a sole proprietorship and a corporation end up with two different BNs — one for each legal entity. Make absolutely sure you are using the BN that corresponds to the legal entity actually issuing the invoice. The entity name on the invoice must match the entity name on the GST/HST registration. Mixing up the numbers between your personal and corporate accounts is a common error when freelancers incorporate mid-career.