How to Add HST and GST to Your Invoice as a Canadian Contractor
Learn exactly what CRA requires on a GST/HST invoice, when you must register, HST rates by province, and how to correctly display your HST number. Updated for 2026.
You crossed the $30,000 mark. Congratulations — and now CRA expects something from you. Canadian contractors who hit that revenue threshold must register for a GST/HST number and start charging tax correctly on every invoice, or risk audits, penalties, and a very uncomfortable letter from the Canada Revenue Agency.
Here's exactly what your invoices need to say, which rate to charge, and when you must remit.
- Register for GST/HST once you earn over $30,000 CAD in any single quarter or across four consecutive quarters.
- Invoices under $30 CAD need your name, date, total, and tax amount.
- Invoices of $30 to $149.99 CAD also require the buyer's name and a service description.
- Invoices of $150 CAD or more must include your 9-digit Business Number (BN) with RT 0001 suffix.
- Always show GST/HST as a separate line item — never bundled into the total.
Do You Even Need to Charge GST/HST? (The $30,000 Rule)
Most new Canadian contractors don't charge GST/HST at first — and that's perfectly legal. CRA classifies you as a "small supplier" if your total worldwide taxable revenues stay under CAD $30,000 across any single calendar quarter or across four consecutive calendar quarters.
The moment you exceed that threshold, the clock starts. You have 29 days to register for a GST/HST number — no grace period, no extensions. We see contractors get blindsided by this all the time, especially in their second year when revenue accelerates and the threshold gets crossed mid-quarter.
Below that threshold, charging GST/HST is optional. But here's the thing: voluntary registration lets you claim Input Tax Credits (ITCs) on your own business expenses — software, equipment, subcontractors. For many contractors, registering early actually saves money.
What CRA Requires on Every GST/HST Invoice
CRA's invoice requirements are tiered by invoice amount, per GST/HST Memorandum 3.6. A lot of contractors apply the top-tier rules to everything — that's fine. But at minimum, you need to meet the requirements for your invoice value.
| Invoice Amount | Required Elements |
|---|---|
| Under $30 CAD | Supplier name · Invoice date · Total charged · GST/HST amount or rate |
| $30 – $149.99 CAD | Everything above + buyer's name + brief description of goods or services |
| $150 CAD or more | Everything above + your 9-digit Business Number with RT 0001 suffix (e.g., 123456789 RT 0001) |
That BN requirement on $150+ invoices is the one contractors most often get wrong. A missing or incorrect BN isn't just a paperwork issue — it's an auditable offense. Using GST/HST invoice templates that pre-populate the BN field is the simplest way to avoid that mistake entirely.
CRA can deny your client's Input Tax Credit claim if your GST/HST number is missing or wrong on the invoice — putting your professional relationship at risk and leaving your client out of pocket.
HST Rates by Province + How to Display the Tax Line
The rate you charge depends entirely on where your client is located — specifically, the place of supply. That means a Toronto-based contractor billing a client in Nova Scotia charges 15%, not 13%.
| Province / Territory | Tax Type | 2026 Rate |
|---|---|---|
| Alberta, BC, Manitoba, Saskatchewan | GST only | 5% |
| Yukon, NWT, Nunavut | GST only | 5% |
| Ontario | HST | 13% |
| Nova Scotia, New Brunswick, PEI, Newfoundland & Labrador | HST | 15% |
| Quebec | GST (5%) + QST (9.975%) — separate registration with Revenu Québec required | 14.975% |
Quebec is the exception everyone forgets. If you're billing clients in Quebec, you need a separate QST registration with Revenu Québec — CRA handles the GST piece, but Revenu Québec handles the provincial portion independently. If you're a sole proprietor just getting started, factor that dual registration into your setup timeline.
Always show tax as a separate line item, state the rate and province, and include your BN RT number. That's the CRA standard — not optional formatting.
Here's what a compliant Ontario invoice looks like at the bottom:
HST 13% (ON) $195.00
Total $1,695.00
GST/HST No. 123456789 RT 0001
Most small contractors file annually and must remit by April 30. If you miss it, CRA's penalty starts at 5% of the balance owing plus 1% per additional month — it compounds fast. Check whether you're on an annual, quarterly, or monthly reporting period, which CRA assigns based on your revenue level.
Create a CRA-Compliant Invoice in Minutes
Getting the format right every time is easier with a tool that handles it for you. Invoicito's invoice templates include pre-built GST/HST line items, a dedicated field for your Business Number, and automatic rate calculation — no manual math, no missing fields.
Canadian contractors: charge the right rate for your client's province, show your BN on every invoice of $150 or more, and remit on time. A compliant invoice protects both your tax position and your client's ability to claim Input Tax Credits.
Frequently Asked Questions
Do I have to charge GST if I make less than $30,000 as a contractor?
No. If your total worldwide taxable revenues stay under CAD $30,000 across any four consecutive calendar quarters, you qualify as a "small supplier" and are not required to register or collect GST/HST. You may still register voluntarily to claim Input Tax Credits on your business expenses — often worth doing from day one.
What is the difference between GST and HST on a Canadian invoice?
GST (Goods and Services Tax) is the federal 5% tax applied in provinces that haven't harmonized with a provincial tax. HST (Harmonized Sales Tax) combines the federal GST with a provincial component — used in Ontario (13%) and Nova Scotia, New Brunswick, PEI, and Newfoundland (all 15%). Both are collected under the same CRA registration number, so you only register once.
Where exactly do I put my GST/HST number on an invoice?
Your 9-digit CRA Business Number followed by "RT 0001" (e.g., 123456789 RT 0001) should appear near the tax line or in the invoice header, labelled "GST/HST No." Per CRA GST/HST Memorandum 3.6, it's mandatory on all invoices of $150 CAD or more.
Get your BN right, apply the correct provincial rate, and keep tax as a visible separate line. That's everything CRA is looking for — and everything your clients need to protect their own tax claims.