GST, PST and HST: The Complete Tax Guide for Canadian Small Businesses

June 9, 2026 · 11 min read

If you run a small business or freelance in Canada, sales tax is one of those things you can't afford to get wrong. The Canada Revenue Agency takes GST/HST seriously, and mistakes — whether overclaiming input tax credits, missing a filing deadline, or charging the wrong rate — can result in penalties, interest, and reassessments that cost far more than the original tax.

The frustrating thing is that the Canadian sales tax system is genuinely complicated. Unlike countries with a single national sales tax rate, Canada has a patchwork of federal and provincial taxes that interact differently depending on where your business is, where your customers are, and what you're selling.

This guide breaks it all down in plain language — what each tax is, what rates apply where, when you need to register, how to file, and how to make sure you're claiming every input tax credit you're entitled to.

The Three Types of Canadian Sales Tax

Canada has three types of sales tax that small businesses need to understand:

GST — Goods and Services Tax

GST is the federal sales tax that applies across Canada. The rate is 5% and it applies to most goods and services sold in Canada. It's administered by the Canada Revenue Agency.

HST — Harmonized Sales Tax

HST is a combination of the federal GST and a provincial component, merged into a single tax. Provinces that have harmonized their provincial tax with the federal GST charge HST instead of GST + separate PST. The rate varies by province but always includes the 5% federal component.

PST — Provincial Sales Tax

PST is a provincial-only tax charged by provinces that have not harmonized with the federal GST. PST is separate from GST — businesses collect and remit them independently, often to different government bodies.

Sales Tax Rates by Province and Territory (2026)

Key takeaway: if your business operates in or sells to customers in multiple provinces, the applicable tax rate depends on the province of supply — generally where the customer receives the goods or services.

Do You Need to Register for GST/HST?

Not every business needs to register for GST/HST right away. Here's how it works:

The $30,000 Threshold

You are required to register for GST/HST once your total revenues from taxable supplies exceed $30,000 CAD in a single calendar quarter or in any four consecutive calendar quarters. This threshold applies to your total revenues, not your profit.

Once you cross $30,000, you must register within 29 days and start collecting GST/HST.

Small Supplier Status

If your revenues are under $30,000, you are considered a "small supplier" and registration is optional. Many small suppliers choose not to register because it simplifies their bookkeeping — they don't charge GST/HST and don't need to file returns.

However, voluntary registration can be beneficial even under $30,000 because it allows you to claim input tax credits (ITCs) — meaning you get back the GST/HST you paid on your business expenses. For businesses with significant expenses (equipment, software, professional services), voluntary registration often results in net money back from the CRA.

Who Must Register Regardless of Revenue

Some businesses must register for GST/HST regardless of revenue: - Taxi and ridesharing operators - Non-resident businesses selling digital services to Canadian consumers - Businesses selling certain financial services

Quebec Businesses

Quebec businesses must also register separately for QST with Revenu Québec. QST registration has the same $30,000 threshold but is a separate registration process from GST.

Understanding Input Tax Credits (ITCs)

Input tax credits are one of the most valuable aspects of being registered for GST/HST — and one of the most commonly misunderstood.

What Is an Input Tax Credit?

When you pay GST/HST on a business expense, you can claim that amount back from the CRA as an ITC. Essentially, you're only required to remit the GST/HST you collect from customers, minus the GST/HST you paid on your business inputs.

Example: - You invoice a client $1,000 + $130 HST (Ontario) = $1,130 collected - You buy $200 in office supplies + $26 HST = $226 paid - You owe the CRA: $130 - $26 = $104

The $26 ITC reduces what you remit. If your ITCs exceed what you collected in a period — common for businesses with high startup costs or equipment purchases — the CRA will issue you a refund.

What Qualifies for an ITC?

To claim an ITC, the expense must: 1. Be a taxable supply (not exempt or zero-rated) 2. Be used at least partially for commercial activities 3. Be supported by a valid receipt or invoice

The CRA has specific documentation requirements for ITCs based on the amount: - Under $30: you need the supplier's name, date, total paid, and indication that GST/HST was included - $30–$149.99: add the GST/HST registration number of the supplier - $150 and over: add a description of the goods/services, the terms of payment, and the GST/HST amount shown separately

This is why keeping organized receipts with all the required information is not just good practice — it's legally required to claim your ITCs.

Expenses You Cannot Claim ITCs For

Not every business expense qualifies for a full ITC: - Meals and entertainment: only 50% of the GST/HST paid is claimable as an ITC (matching the 50% income tax deduction limit) - Personal use portion of mixed-use assets: only the business-use percentage is claimable - Employee benefits: specific rules apply to taxable benefits - Exempt supplies: if your business makes exempt supplies (certain financial services, residential rent, health services), ITCs may be restricted

GST/HST Filing Periods and Deadlines

Once registered, you'll be assigned a filing period based on your annual revenues:

Important: even if you file annually, you may be required to make quarterly instalment payments if your net tax for the previous year exceeded $3,000. Missing instalment payments triggers interest charges.

New Registrants

If you've just registered, the CRA will assign you a filing period. Annual filing is most common for new small businesses. You can request to file more frequently if you prefer — some businesses with consistent ITC refunds prefer quarterly filing to get their refunds faster.

Filing the GST/HST Return

You file your GST/HST return (Form GST34) online through CRA My Business Account or by mail. You report: - Total sales and other revenues - Total GST/HST collected - Total ITCs claimed - Net tax owing or refund

Payment is due at the same time as filing. If you owe money and miss the deadline, the CRA charges compound daily interest plus a late-filing penalty.

Provincial Sales Tax — The Separate System

For businesses in BC, Saskatchewan, Manitoba, and Quebec, PST/RST/QST operates as a completely separate system from GST.

Key Differences from GST/HST

• Separate registration: you register with the provincial government, not the CRA (except QST, which is handled by Revenu Québec)
• No ITC equivalent: unlike GST/HST, most provinces don't allow businesses to claim back PST paid on inputs — it's a cost to your business
• Different rules by province: what's taxable, what's exempt, and how the tax applies varies significantly between provinces

BC PST

• Rate: 7%
• Registration required if you sell taxable goods or services in BC
• Many services are exempt from BC PST (unlike GST/HST which is broadly applied)
• File and remit to BC Ministry of Finance

Saskatchewan PST

• Rate: 6%
• Broader base than most provinces — includes many services
• File and remit to Saskatchewan Finance

Manitoba RST

• Rate: 7%
• Similar structure to PST in other provinces
• File and remit to Manitoba Finance

Quebec QST

• Rate: 9.975%
• Most similar to GST in structure — broad base, ITC-equivalent system (called ITRs — input tax refunds)
• Administered by Revenu Québec, not the CRA
• Must register separately even if already registered for GST

Zero-Rated and Exempt Supplies

Not everything is subject to GST/HST. Understanding the difference between zero-rated and exempt supplies matters for your bookkeeping.

Zero-Rated Supplies (0% GST/HST)

Zero-rated means the supply is technically taxable, but at a 0% rate. You don't charge GST/HST on zero-rated supplies, but you can still claim ITCs on your inputs. Common zero-rated supplies include: - Basic groceries (not restaurant meals or snacks) - Prescription drugs - Most medical devices - Exports of goods and services - International transportation

Exempt Supplies (No GST/HST)

Exempt supplies are not subject to GST/HST at all, and businesses making exempt supplies generally cannot claim ITCs on related inputs. Common exempt supplies include: - Most health care services - Child care services - Educational services (most tuition) - Residential rent (long-term) - Most financial services

Why This Matters for Bookkeeping

When you or your AI bookkeeping tool categorizes a receipt, the tax treatment needs to reflect whether the supply is taxable, zero-rated, or exempt. An expense coded as "no tax" when GST/HST was actually included means a missed ITC. An expense coded with GST/HST when the supply was exempt means an overclaimed ITC — which the CRA can assess and reverse with interest.

Common GST/HST Mistakes Canadian Small Businesses Make

Not Registering on Time

Many small business owners don't realize they've crossed the $30,000 threshold until they're already past it. The obligation to register — and to retroactively remit GST/HST on sales made after crossing the threshold — is automatic. Missing the registration window triggers penalties and back-remittance obligations.

Track your revenues quarterly and register as soon as you approach $30,000.

Charging the Wrong Rate

Using a flat 13% HST when you're shipping goods to Alberta (5% GST only) or British Columbia (5% GST + 7% PST) overcharges your customer and creates reconciliation issues. The rate depends on where the customer receives the supply, not where your business is located.

Missing the ITC Documentation Requirements

The CRA regularly denies ITCs during audits because businesses can't produce receipts that meet the documentation requirements. A credit card statement alone is generally not sufficient — you need the actual receipt showing the supplier's GST/HST registration number for purchases over $30.

Mixing Personal and Business Expenses

ITCs can only be claimed on business expenses. If personal expenses flow through your business accounts, you either over-claim ITCs (CRA audit risk) or spend time sorting through transactions to remove personal items. A dedicated business account eliminates this problem.

Not Remitting on Time

Late remittance triggers both interest (currently compounded daily at the prescribed rate plus 4%) and a late-filing penalty. For businesses that owe money, even one missed deadline creates a cascade of charges that compounds over time.

How AI Bookkeeping Handles GST/HST/PST

Managing Canadian sales tax manually is error-prone precisely because it requires applying different rules to every transaction based on province, supply type, and tax registration status. This is exactly the kind of rule-based work that AI bookkeeping handles well.

A purpose-built Canadian AI bookkeeping tool: - Automatically identifies the tax component on every receipt and invoice - Separates GST, HST, and PST correctly based on the supplier province - Flags zero-rated and exempt supplies for review - Tracks ITC-eligible amounts separately from non-eligible amounts (like the 50% meals limit) - Produces clean reports showing total GST/HST collected and total ITCs claimable — exactly what you need to complete your return

Instead of manually reviewing every receipt to extract the tax component and check whether it qualifies for an ITC, the AI does it automatically and consistently — reducing errors and saving hours every reporting period.

Quick Reference: GST/HST Checklist for Small Businesses

• Track revenues quarterly — register within 29 days of exceeding $30,000
• Confirm which tax applies based on province of supply, not your location
• Keep all receipts with GST/HST registration numbers for purchases over $30
• Note the 50% ITC limit for meals and entertainment
• File GST/HST returns on time — annual, quarterly, or monthly based on revenue
• If in Quebec, register for QST separately with Revenu Québec
• If in BC, Saskatchewan, or Manitoba, register for PST separately
• Review your ITCs quarterly — refunds are available if ITCs exceed tax collected

The Bottom Line

Canadian sales tax is one of the more complex aspects of running a small business in this country. The multi-rate, multi-province system means there's no single answer to "what rate do I charge?" — it depends on where your customer is, what you're selling, and which province's rules apply.

The good news is that once you understand the structure, the rules are consistent and manageable. Register on time, charge the right rate, keep your receipts, claim your ITCs, and file on time. Organized bookkeeping makes all of this straightforward — and that's exactly what AI bookkeeping is designed to help you do.

AI Bookkeeping by Time2Win Inc. is built specifically for Canadian and US small businesses, with built-in GST/HST/PST awareness and automatic tax identification on every receipt. Try it free at ai-bookkeeping.ai.