If you have ever tried to close a client's books in April and realized their HST number was never set up properly, you know the frustration. A missed registration deadline can mean backdated penalties, interest, and a tense conversation with the CRA. Whether you are a bookkeeper managing multiple GST/HST accounts or a small business owner starting a side hustle, understanding how to get an HST number in Canada is a foundational step. This guide walks through the registration process for 2026, including thresholds, forms, and what to do after you receive your number.

Table of Contents

  • Who Needs to Register for an HST Number?
  • How to Register for an HST Number: Step by Step
  • After Registration: Filing, Returns, and Remittances
  • Common Registration Mistakes and How to Avoid Them
  • Frequently Asked Questions
  • What to Do Next

Who Needs to Register for an HST Number?

Not every business in Canada needs an HST number. The CRA sets a threshold based on your taxable supplies over the previous four consecutive calendar quarters. If your worldwide taxable revenues exceed $30,000 in a single quarter or over the trailing four quarters, you are required to register. This threshold applies to most businesses, including sole proprietors, partnerships, and corporations. There is a lower threshold of $30,000 for public service bodies such as charities and non-profits, but the general rule is the same.

If you earn less than $30,000, you can still voluntarily register. Voluntary registration can be useful if you have significant input tax credits (ITCs) to recover, but it also means you must charge HST on your sales and file regular returns. Many small service businesses choose to stay under the threshold to avoid the administrative burden, but once you exceed it, you have no choice. You must register within 29 days of exceeding the threshold. If you miss this window, the CRA can impose penalties and interest on the HST you should have collected from the date you exceeded the limit.

Provincial Considerations: HST vs GST vs QST

Canada uses a harmonized sales tax (HST) in five provinces: Ontario, New Brunswick, Newfoundland and Labrador, Nova Scotia, and Prince Edward Island. In these provinces, the HST rate combines the federal GST and provincial PST into one rate. British Columbia, Saskatchewan, Manitoba, and Quebec use separate GST and provincial sales tax (PST or QST). Alberta, the territories, and some other regions use only the federal GST. When you register for a GST/HST number, the CRA automatically assigns the correct provincial code based on your business address. If you operate in Quebec, you may also need a separate QST number from Revenu Quebec, though the federal registration process covers the GST portion.

How to Register for an HST Number: Step by Step

Registering for an HST number in Canada is straightforward if you have the right information ready. The CRA offers two main methods: online through the Business Registration Online (BRO) service, or by mail using Form RC1. Most businesses use the online method because it is faster and provides your HST number immediately. Here is the step-by-step process.

Step 1: Gather Required Information

Before you start, collect the following:

  • Your Social Insurance Number (SIN) or Business Number (BN) if you already have one.
  • Legal name and business name (if different).
  • Business address and mailing address.
  • Business structure (sole proprietorship, partnership, corporation).
  • Estimated annual revenue from taxable supplies.
  • Date you exceeded or expect to exceed the $30,000 threshold.
  • Bank account information for direct deposit of refunds (optional but recommended).

If you are incorporating or already have a corporation, you need your incorporation number and the date of incorporation.

Step 2: Access Business Registration Online

Go to the CRA's Business Registration Online service. You will need a CRA My Account or a Represent a Client account if you are an authorized representative. If you do not have one, you can create a CRA user ID and password. Once logged in, select "Register a new business" or "Add a new program account" to your existing Business Number. The system will walk you through the questions.

Step 3: Complete the Registration Form

The online form asks about your business activities, expected revenue, and fiscal year-end. Be accurate about your revenue estimates, because the CRA uses them to set your filing frequency (annual, quarterly, or monthly). If you underestimate, you may end up with a filing frequency that does not match your actual revenue, leading to late-filing penalties. After submitting, you will receive your HST number (formatted as a 9-digit Business Number followed by a two-letter program identifier, e.g., 123456789 RT0001) immediately. Print or save the confirmation.

Step 4: If You Prefer Paper

You can also complete Form RC1, Request for a Business Number and Certain Program Accounts. Mail it to your tax services office. Processing takes 4-6 weeks. This method is slower, so it is best for businesses that are not yet earning revenue or that prefer a paper trail. Once processed, the CRA will mail your HST number.

After Registration: Filing, Returns, and Remittances

Once you have your HST number, the real work begins. You must charge HST on all taxable supplies (with some exceptions like basic groceries, child care, and health services). You must also file returns on a schedule determined by the CRA, usually quarterly for most small businesses with annual taxable supplies under $1.5 million. If your revenue exceeds $1.5 million, you file monthly. Annual filing is available for businesses with revenue under $400,000, but you must remit quarterly installments if your net tax exceeds $3,000.

Filing a GST/HST Return

Returns are due one month after the end of your reporting period. For example, if you file quarterly for periods ending March 31, June 30, September 30, and December 31, your return is due by the end of the following month. You can file online through the CRA's My Business Account or through most accounting software. The return reports your total sales, HST collected, and input tax credits (ITCs) for purchases. If your ITCs exceed the HST you collected, you get a refund. If you collected more than you paid, you remit the difference.

Remittance Options

You can remit online via the CRA's My Payment service, through your financial institution, or by cheque. Many businesses set up pre-authorized debit to avoid missing deadlines. Late remittances attract interest at the prescribed rate, which the CRA updates quarterly. In 2025, the rate was around 9% annually, so missing a payment is expensive. If you are managing multiple client files, using a practice management platform that integrates with the CRA can help track deadlines and avoid surprises.

Common Registration Mistakes and How to Avoid Them

Even experienced accountants slip up on HST registration details. Here are the most frequent errors and how to handle them.

Mistake 1: Registering too late. The 29-day rule is strict. If you exceed $30,000 in a quarter on March 15, you must register by April 13. If you wait until April 20, the CRA may assess penalties. The penalty is 1% of the HST you should have collected, plus 25% of that amount for each month you are late, up to a maximum of 12 months. To avoid this, track your revenue monthly, especially in the first year of operation.

Mistake 2: Choosing the wrong filing frequency. When you register, the CRA asks for your estimated annual taxable supplies. If you say $200,000, you get quarterly filing. If you later grow to $2 million, you must switch to monthly. If you do not switch voluntarily, the CRA may reassess and charge penalties for late monthly filings. Review your revenue annually and update your filing frequency through your CRA account.

Mistake 3: Not registering for QST in Quebec. If your business is in Quebec or has a permanent establishment there, you may need a separate QST number. The GST/HST registration does not cover QST. You must register with Revenu Quebec using their process. The QST rate is 9.975% (as of 2026) on most goods and services, applied on the selling price excluding GST. If you sell to Quebec consumers, you must charge both GST and QST.

Mistake 4: Forgetting to update your business information. If you move, change your business structure, or close, you must update your CRA account. Failure to do so can result in mail being sent to the wrong address, leading to missed notices and penalties. Keep your contact information current.

Manual vs Automated Workflow

Consider the difference between tracking HST registration deadlines manually and using integrated accounting software. A bookkeeper who manages 20 small clients might rely on spreadsheets and calendar reminders. When a client exceeds the threshold in early March, the bookkeeper must remember to register within 29 days, update the accounting system, and adjust invoices. If the reminder fails, penalties accumulate. With an automated system that flags revenue thresholds and integrates with CRA services, the entire process becomes proactive. For example, many Canadian CPA firms centralize client work in one practice management platform that tracks filing frequencies and sends reminders. The time saved on administrative follow-up can be redirected to higher-value advisory work.

Frequently Asked Questions

Do I need an HST number if I only sell to the US?

Yes, if your worldwide taxable supplies exceed $30,000, you must register. The threshold applies to all supplies, not just Canadian sales. However, sales to US customers are typically zero-rated for GST/HST purposes, meaning you do not charge HST on them, but you still must include them on your return and can claim ITCs for related expenses.

Can I register for an HST number before I start earning revenue?

Yes, you can voluntarily register even if you have not yet earned $30,000. This is common for startups that plan to make significant purchases and want to recover ITCs early. Once registered, you must charge HST on any sales and file returns, even if your sales are zero.

What is the difference between a Business Number and an HST number?

Your Business Number (BN) is a 9-digit identifier for your business with the CRA. An HST number is a program account under that BN, shown as the BN plus a two-letter suffix like RT0001. You can have multiple program accounts under one BN, such as payroll deductions (RP), import/export (RM), and GST/HST (RT).

How do I cancel my HST number?

If you stop making taxable supplies or your revenue drops below $30,000, you can request cancellation. Log into your CRA My Business Account and select "Close a program account." You must file a final return and remit any HST owed. If you close without filing, the CRA may assess based on estimated amounts.

What happens if I do not register on time?

The CRA can assess you for the HST you should have collected from the date you exceeded the threshold. You will also face a penalty of 1% of the amount, plus 25% of that penalty for each month late, to a maximum of 12 months. Interest accrues on the unpaid amount at the prescribed rate.

What to Do Next

Getting your HST number correct from the start saves time, money, and stress. Verify your revenue against the $30,000 threshold regularly, especially in growing months. If you are already registered, review your filing frequency and update it if your revenue has changed. For accounting firms managing multiple clients, consider using a platform that automates registration tracking and filing reminders. Awditify's tools for small businesses and accounting firms integrate with your workflow to keep HST compliance on track. To see how it fits your practice, book a demo or explore our GST/HST resources.