The Complete Guide to GST/HST for Canadian Small Business
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Table of Contents
What GST/HST Actually Is
The single most useful thing to understand about GST/HST is that it is not your money and it is not your tax. You are an unpaid collection agent for the federal government.
Goods and Services Tax is a 5% federal value-added tax that applies to most goods and services sold in Canada. In five provinces it is combined with the provincial sales tax into a single Harmonized Sales Tax, administered by the CRA under one return. In the rest of the country, GST sits alongside a separate provincial tax — or, in Alberta and the three territories, alongside nothing at all.
“Value-added” is the part that trips people up. You charge tax on what you sell, you pay tax on what you buy, and you send the government the difference. If you collected $4,000 in a quarter and paid $1,500 on business expenses, you remit $2,500. The tax is designed to fall on the final consumer, and businesses in the chain should end up neutral.
This is why treating GST/HST as revenue is the most common and most damaging bookkeeping mistake we see. An owner looks at a healthy bank balance in month two of a quarter, spends against it, and then discovers in month four that a meaningful chunk of it belonged to the Receiver General. If you take nothing else from this guide: move the tax out of your operating account the moment you invoice, or at minimum every month.
A note on terminology
You will see “GST/HST” written as one thing throughout CRA material because it is one tax with two rates depending on province. There is no separate HST return. If you are registered, you are registered for both, and you charge whichever applies to the transaction.
Key Takeaways
- You must register once your taxable revenue passes $30,000 over four consecutive calendar quarters — that’s worldwide revenue from taxable sales, not profit.
- The rate depends on where your customer is, not where you are. A Winnipeg consultant billing a Toronto client charges 13%, not 5%.
- You only remit the difference between tax you collected and tax you paid on business purchases. The money you collect was never yours.
- Most small businesses file annually (revenue under $1.5 million), but may owe quarterly instalments if their net tax hits $3,000.
- Late-filing penalties are modest; failing to register on time is expensive, because the CRA can assess the tax you should have charged.
Do You Have to Register?
You are a small supplier — and therefore not required to register — while your total taxable revenue stays at or below $30,000 over four consecutive calendar quarters. Three details about that sentence matter more than the number itself.
It is revenue, not profit. A sole proprietor who bills $44,000 and nets $19,000 after expenses is over the threshold. The test never looks at your margin.
It is a rolling four-quarter window, not a calendar year. The four quarters ending 30 September are just as capable of putting you over as the four ending 31 December. Many owners check once a year in April and discover they crossed the line the previous summer.
It is worldwide taxable revenue, including zero-rated sales. Zero-rated supplies — exports, basic groceries, most prescription drugs and medical devices — are taxable at 0%, which still counts toward the threshold. Genuinely exempt supplies, such as most residential rent, most health care services and most financial services, do not.
Crossing the threshold: two different consequences
How you cross matters, because the CRA treats the two cases differently.
If you exceed $30,000 in a single calendar quarter, you stop being a small supplier immediately. You are considered registered as of the sale that pushed you over, and you must charge GST/HST on that very sale. There is no grace period.
If you exceed $30,000 cumulatively across four consecutive quarters but not in any single one, you remain a small supplier for one additional month. You must be registered by the first day of the month after that, and charge tax from that date.
Miss either deadline and the CRA can assess you for tax you should have collected but didn’t — which you now owe out of your own pocket, because you cannot realistically go back to customers a year later and ask for another 13%. This is the expensive failure mode, and it is far more costly than any late-filing penalty.
Registering voluntarily is often the better call
Below $30,000 you may register anyway, and frequently should. If you sell mainly to other registered businesses, your prices are effectively unchanged to them — they claim back what you charge — while you start recovering tax on your own equipment, software, fuel and professional fees. The calculus flips if you sell mainly to consumers, where adding 13% is a real price increase you absorb or pass on. Businesses with heavy start-up purchases often register early purely to recover the tax on them.
What Rate Do You Charge?
The rate is set by the place of supply — broadly, where the customer receives the goods or services — not by where your business is located. A Vancouver bookkeeper serving a client in Halifax charges Nova Scotia’s rate.
| Province / Territory | Type | Total rate | Notes |
|---|---|---|---|
| Ontario | HST | 13% | 5% federal + 8% provincial |
| Nova Scotia | HST | 14% | Reduced from 15% on 1 April 2025 |
| New Brunswick | HST | 15% | |
| Newfoundland & Labrador | HST | 15% | |
| Prince Edward Island | HST | 15% | |
| British Columbia | GST + PST | 5% + 7% | PST filed separately with the province |
| Manitoba | GST + RST | 5% + 7% | RST filed separately with the province |
| Saskatchewan | GST + PST | 5% + 6% | PST filed separately with the province |
| Quebec | GST + QST | 5% + 9.975% | Both administered by Revenu Québec |
| Alberta | GST only | 5% | No provincial sales tax |
| Yukon, NWT, Nunavut | GST only | 5% | No territorial sales tax |
The separate provincial taxes in BC, Manitoba, Saskatchewan and Quebec are a genuinely different system with their own registration rules, returns and deadlines, and — importantly — no equivalent of input tax credits in most cases. PST paid on business inputs is usually a cost, not a recoverable amount. Businesses operating across those provinces carry a real compliance burden that HST provinces do not.
Claiming Input Tax Credits
An input tax credit (ITC) is your claim for GST/HST paid on purchases made to earn taxable revenue. It is the mechanism that keeps the tax from compounding at every stage, and it is where most recoverable money goes unclaimed.
You can claim ITCs on essentially any business input that carries tax: inventory, equipment, software subscriptions, professional fees, commercial rent, fuel, advertising, phone and internet. Where an expense is partly personal — a home office, a vehicle used for both — you claim only the business proportion, and you need a defensible basis for that split.
Documentation is the whole game
ITC claims are the single most common target in a CRA review, and they are usually denied for missing paperwork rather than ineligibility. The documentation required scales with the amount:
- Under $100: supplier name, date, and total amount paid.
- $100 to $499.99: the above, plus the supplier’s GST/HST registration number and either the amount of tax charged or a statement that the total includes it.
- $500 and over: all of the above, plus the buyer’s name, the terms of payment, and a description of the goods or services.
These are the thresholds in force since 20 April 2021, when they were raised from the old $30 and $150 tiers. Amounts are the total including tax. Older guidance still circulating quotes the previous figures.
A credit card statement is not sufficient documentation. It proves you spent money; it does not prove tax was charged, by whom, or on what. Keep the actual receipt or invoice — which is why receipt-capture tools have become standard practice rather than a nicety.
You generally have four years to claim an ITC you missed, so a catch-up exercise on a neglected year is usually still worth doing.
The registration number check
If a supplier charges you tax but isn’t actually registered, your ITC can be denied — you were never charged legitimate GST/HST. For any significant recurring supplier, confirm the number in the CRA’s GST/HST Registry once, at the start of the relationship. It takes a minute and it is the kind of thing that only matters after an audit has already started.
Choosing a Filing Frequency
The CRA assigns a default reporting period based on your annual taxable supplies:
| Annual taxable supplies | Default period | Can you elect more often? |
|---|---|---|
| $1.5 million or less | Annual | Yes — monthly or quarterly |
| Over $1.5M to $6 million | Quarterly | Yes — monthly |
| Over $6 million | Monthly | Already the most frequent |
You can always elect to file more frequently than your default, never less. That sounds like a burden to take on voluntarily, but there are two good reasons to do it.
The first is cash discipline. Annual filers accumulate twelve months of collected tax and then face a single large payment, which is precisely the situation where the money has quietly been spent. Quarterly filing keeps the liability visible and the amounts survivable.
The second is refunds. If you are consistently in a refund position — common for exporters, for businesses in a heavy investment phase, and for anyone selling mostly zero-rated goods — annual filing means lending the government your money for up to a year. Monthly filing gets it back promptly.
Annual filers whose net tax for the year is $3,000 or more must make quarterly instalment payments toward the following year, each due one month after the quarter ends. Miss them and the CRA charges instalment interest even if the final return is filed on time.
The Quick Method
The Quick Method is a simplification available to businesses with annual taxable supplies of $400,000 or less including GST/HST. Instead of tracking ITCs on every purchase, you charge tax normally but remit a reduced flat percentage of your tax-included revenue, and keep the difference.
The remittance rate depends on your province and on whether you mainly sell goods or services. Service businesses in HST provinces get a rate well below the rate they charge, and the gap is real profit. There is also a 1% credit on the first $30,000 of eligible supplies each year.
The trade-off is that you give up ITCs on operating expenses. You may still claim them on capital purchases like equipment and vehicles, but not on rent, software, supplies or subcontractors. That makes the Quick Method attractive for low-overhead service businesses — consultants, trades with few materials, professional practices — and unattractive for anyone with significant taxable inputs.
The arithmetic is specific to your numbers. Run both methods on a full year of actual data before electing; the difference is frequently a four-figure sum in either direction.
Deadlines and Payments
| Filer type | Return due | Payment due |
|---|---|---|
| Monthly | One month after period end | Same date |
| Quarterly | One month after period end | Same date |
| Annual — corporation | Three months after fiscal year end | Same date |
| Annual — self-employed individual with a 31 Dec year end | 15 June | 30 April |
That last row is a genuine trap and worth reading twice. The filing deadline and the payment deadline are six weeks apart. Interest starts running from 30 April on any balance owing, even though your return isn’t late until 15 June. Plan to have the number by April. Self-employed filers can find the rest of their obligations in our sole proprietor tax guide, and every date for the year is in the Canadian small business tax deadlines calendar.
The late-filing penalty is calculated as 1% of the amount owing, plus 25% of that 1% multiplied by the number of complete months the return is late, to a maximum of twelve months. On a $10,000 balance three months late that is roughly $175 — unpleasant but survivable. Interest compounds daily on top. If you cannot pay, file anyway: the penalty is driven by the unfiled return, and filing on time with a balance owing costs you only interest.
What Goes Wrong Most Often
In our practice, the same handful of problems account for the large majority of GST/HST cleanup work.
Spending the tax. Already covered, and still number one. A separate savings account with an automatic transfer solves it permanently.
Charging the wrong provincial rate. Usually a business that set up its accounting software with one default rate and never revisited it after landing out-of-province clients. The error compounds silently across hundreds of invoices.
Claiming ITCs on exempt or personal expenses. Client meals are only 50% deductible for income tax, and the ITC follows the same restriction. Personal use portions of vehicles and home offices need documented reasoning.
Missing registration by months. Almost always a business that grew faster than expected and checked the threshold once a year.
Filing nil returns while inactive. If you are registered you must file every period, even with no activity. Unfiled nil returns accumulate penalties and can trigger arbitrary CRA assessments that are a real nuisance to unwind.
Common Questions
Do I charge GST/HST to a US client?
Generally no — exports of goods and services to non-residents are usually zero-rated, meaning you charge 0% but still claim ITCs on related inputs. The rules around what qualifies are more technical than they first appear, particularly for services and intangibles, so confirm your specific situation rather than assuming. Consultants with foreign clients will find more in our guide to bookkeeping for consultants, and online sellers in bookkeeping for e-commerce businesses.
What if I registered but haven’t hit $30,000?
Then you charge, collect and remit like any other registrant. Voluntary registration carries the same obligations as mandatory registration, including filing every period. You must generally stay registered for at least one year before deregistering.
Can I claim ITCs on purchases made before I registered?
In limited circumstances, yes — notably on inventory on hand and certain capital property at the time of registration. This is worth asking about if you registered after a period of significant purchasing.
My customer won’t pay the tax. Now what?
You still owe it. GST/HST is payable on the invoice date under accrual accounting, regardless of whether you have been paid. If the debt genuinely goes bad you may be able to recover the tax through a bad debt adjustment, but you cannot simply omit it.
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