Insights
Nov 12, 2025
Mackisen
How to Register for HST When Expanding Outside Quebec
Introduction
As Quebec businesses grow beyond provincial borders, many entrepreneurs find themselves facing a new challenge: understanding how to register for HST (Harmonized Sales Tax) in other provinces. Expanding from Quebec into Ontario, Nova Scotia, New Brunswick, Newfoundland, or Prince Edward Island means your company must comply with federal and provincial sales tax rules simultaneously.
The process can be confusing—each province has its own rules, thresholds, and registration requirements. But failure to register for HST on time can trigger CRA reassessments, interest under the Excise Tax Act, and even penalties under Tax Administration Act s.94.1 for non-compliance.
At Mackisen CPA Montreal, we help Quebec-based companies expand safely across Canada by ensuring full GST/HST registration, proper invoicing, and seamless accounting system integration.
Legal and Regulatory Framework
Sales tax registration outside Quebec is governed by the Excise Tax Act (Canada).
Section 240(1) requires every person making taxable supplies in Canada to register for GST/HST once they exceed $30,000 in taxable sales over four consecutive calendar quarters.
The same section applies to Quebec companies expanding into HST provinces—Ontario, Nova Scotia, New Brunswick, Newfoundland and Labrador, and Prince Edward Island.
Businesses registered for QST in Quebec are not automatically registered for HST.
In those provinces, HST replaces GST and provincial sales tax (PST), creating a single combined tax rate that varies by region:
Ontario – 13%
Nova Scotia – 15%
New Brunswick – 15%
Newfoundland and Labrador – 15%
Prince Edward Island – 15%
Failure to register and charge the appropriate HST rate can result in retroactive assessments under Excise Tax Act s.296 and daily compounding interest under s.280(1).
When to Register for HST
You must register for HST if:
Your business sells taxable goods or services to customers located in an HST province.
You exceed $30,000 in total taxable supplies (including sales inside and outside Quebec).
You carry out regular commercial activity in those provinces (e.g., online sales, deliveries, or in-person projects).
If your sales are under $30,000, you may register voluntarily to recover input tax credits (ITCs) on your business purchases. This can provide a financial advantage, especially if you buy inventory or equipment in HST provinces.
Step-by-Step: How to Register for HST When Expanding Outside Quebec
Review Your Sales Data
Calculate your total taxable sales (including Quebec).
Identify where your customers are located and whether they are subject to HST.
Register with the CRA
Access the CRA’s Business Registration Online (BRO) portal.
Add the “GST/HST program account” (RT0001) to your existing Business Number.
Indicate the effective date of registration and expected revenues.
Determine the Correct HST Rate by Province
Apply 13% in Ontario.
Apply 15% in Nova Scotia, New Brunswick, Newfoundland, and Prince Edward Island.
Continue to apply GST (5%) + QST (9.975%) for Quebec customers.
Update Your Invoicing and Accounting System
Configure your POS or accounting software to apply the correct HST rate by region.
Clearly show the HST rate, amount, and registration number on each invoice.
File and Remit HST
File returns monthly, quarterly, or annually, depending on your sales.
Remit HST through the CRA portal and ensure payments are on time to avoid interest charges.
Jurisprudence and Legal Insights
The courts have confirmed the CRA’s right to assess and collect unpaid HST from businesses that fail to register or charge the correct rate.
Canderel Ltd. v. Canada (SCC 1998): Business income must reflect commercial reality—errors in tax collection create reassessable liabilities.
Hickman Motors Ltd. v. Canada (SCC 1997): CRA assessments are presumed correct unless the taxpayer provides evidence to the contrary.
Lac d’Amiante du Québec Ltée (SCC 2001): Federal and provincial agencies can share information for audit and enforcement.
These cases emphasize that expanding businesses must take HST registration seriously and maintain consistent, verifiable records for all provinces.
Documentation: Building a Cross-Province Compliance File
When you expand outside Quebec, your documentation must show:
Sales by province with HST rate applied.
Proof of delivery or customer location (to confirm correct tax jurisdiction).
Copies of HST returns and remittance confirmations.
Supplier invoices showing tax paid in HST provinces.
Monthly reconciliations verifying HST collected vs. remitted.
Revenu Québec and CRA share audit data across provinces. Poor documentation can trigger simultaneous reassessments under both agencies. At Mackisen CPA Montreal, we build your “HST Audit File” —a digital binder with all necessary evidence to defend your business.
Common Mistakes Businesses Make
Charging QST instead of HST for out-of-province customers.
Ignoring the $30,000 nationwide threshold.
Filing GST-only returns for HST provinces.
Applying the wrong tax rate in e-commerce sales.
Not updating accounting systems for multi-jurisdiction sales.
Each of these mistakes can result in double taxation, refunds denied, or backdated assessments under Excise Tax Act s.296.
How CRA and Revenu Québec Conduct HST Audits
The CRA uses “place of supply” rules to determine which provincial tax applies. If the CRA finds that you sold goods or services to customers in HST provinces without charging the proper tax, it can:
Issue a Notice of Assessment for the unpaid HST.
Apply daily interest under s.280(1).
Freeze refunds or credits until the balance is paid.
Revenu Québec may also reassess your QST filings if discrepancies are found. Mackisen’s tax lawyers and CPA auditors coordinate your defense across both agencies to prevent double penalties.
Winning With CRA and Revenu Québec
Our 35+ years of experience at Mackisen CPA Montreal have proven that winning with tax authorities requires documentation, diplomacy, and deep understanding of interprovincial tax law.
Our Winning Steps for HST Expansion Success
Compliance Audit – We review your existing GST/QST setup to identify missing registrations or rate errors.
Strategic HST Registration – We handle CRA registration, ensuring all provinces are properly set up.
Documentation and Proof – Our auditors build a digital compliance file with all invoices, remittances, and records ready for verification.
Representation and Settlement – If reassessed, our tax lawyers negotiate under CRA Policy P-148 and Tax Administration Act s.94.1 for penalty reduction.
System Integration – We configure accounting systems to automatically apply the correct tax rates per province.
Our philosophy is simple: compliance first, optimization always.
Mackisen Service Hub: Expanding Your Business With Confidence
The Mackisen Service Hub provides end-to-end support for growing Quebec businesses. Our team includes:
CPA Auditors with federal and provincial tax registration expertise.
Tax Lawyers experienced in CRA and Revenu Québec negotiations.
Accounting System Specialists for HST automation.
Business Advisors who plan growth strategies across provinces.
Our professionals—graduates from McGill University, Université de Montréal, and Concordia University—combine academic knowledge with decades of field experience in Canadian tax compliance and corporate growth.
Real Client Example
A Montreal design company expanded sales into Ontario and Nova Scotia without realizing HST applied. CRA reassessed $72,000 in unpaid taxes plus interest. Mackisen CPA registered them retroactively, reconstructed all invoices, and filed a voluntary disclosure under Excise Tax Act s.285. CRA waived 90% of penalties and accepted future compliance agreements.
Why Mackisen
With over 35 years of combined CPA and legal experience, Mackisen CPA Montreal is Quebec’s trusted partner for interprovincial tax compliance. We help you register, file, and grow safely—so your business expansion brings profits, not penalties.
When you expand outside Quebec, trust Mackisen to manage your GST, QST, and HST with precision, professionalism, and peace of mind.
