Most articles about Canadian invoice requirements are out of date. They will tell you the CRA has three tiers of documentation set at $30 and $150. Those thresholds were replaced by $100 and $500, effective April 20, 2021, and plenty of pages published this year still quote the old numbers.
If you have been building invoices against a five-year-old blog post, it is worth ten minutes to check. Here is what the rules actually say, and what happens if your invoice falls short.
The documentation rules exist for the buyer's benefit, not the seller's. When your client pays your invoice, they want to claim the GST or HST you charged as an input tax credit against their own remittance.
If your invoice is missing a required field, the CRA can deny that claim. Your client is out the tax, and the conversation you have next is not about your work.
Incomplete invoices are one of the most common reasons input tax credits get disallowed on audit. A compliant invoice isn't box-ticking — it's a small professional courtesy your client only notices if you get it wrong.
What you must show depends on the total amount on the invoice.
The minimum:
At this level you do not have to break the tax out separately. A coffee-shop receipt clears this bar.
Everything above, plus:
That number is your nine-digit business number followed by the program identifier, in the format 123456789RT0001 — not just the nine digits. The full string.
This is the tier where claims most often fail, and almost always for the same reason: the registration number is missing. Without it, your client cannot claim the credit, and there is no workaround after the fact beyond asking you to reissue.
Everything above, plus:
That last one deserves attention. "Consulting services — $12,000" is the kind of line item that attracts questions. "Strategic planning engagement, March 2026, 40 hours at $300/hr" does not. The description has to be sufficient to show what was actually bought and whether tax applied correctly.
The regulation refers to the total amount payable shown on the document. Where an invoice sits close to a boundary, the safe move is to treat it as the higher tier.
An invoice of $460 plus 13% HST comes to $519.80. Anyone eyeballing the subtotal would file that under the middle tier. The total says otherwise.
You can avoid the question entirely by putting all the information on every invoice regardless of size. There is no penalty for including more than required, and it removes a decision you would otherwise have to make each time.
The CRA runs a public registry where anyone can confirm a GST/HST account number is valid and active. Larger clients, and most accounts-payable departments, will check. A number that comes back cancelled or invalid means the credit is denied outright — even if the work was real and the payment cleared.
Two practical consequences: make sure the number on your invoice template is correct and current, because a typo you never notice will quietly cause your clients problems; and if you are not registered, do not put a number-shaped thing on the invoice, and do not charge GST/HST at all.
You must register once your taxable revenue passes $30,000 in a single calendar quarter, or over four consecutive quarters. Below that you are a small supplier and registration is optional.
If you are not registered, your invoice should show no GST or HST and no registration number. Charging tax you are not registered to collect is a problem of a different order, and one your accountant will find.
Many people register voluntarily before they hit the threshold, because registration lets you claim input tax credits on your own purchases. If you are buying equipment or software, that can be worth more than the administrative cost.
Electronic invoices are fine. The CRA accepts them provided the required information is present and the records are retained and readable.
Retention is the part people skip. Business records supporting a claim generally need to be kept for six years from the end of the tax year they relate to. A PDF in a folder counts. An invoice that only exists inside a tool you stopped paying for does not.
That last point is worth checking on whatever you use to invoice today: if your subscription lapsed tomorrow, could you still produce six years of invoices?
Put all of it on every invoice:
That covers every tier, removes the judgment call, and means no client ever has to come back to you for a reissue. Our free Canadian invoice template already includes every field, and the practical invoice checklist covers what gets you paid faster.
Rules verified against CRA guidance, August 2026. This is general information about invoice documentation, not tax advice — your own circumstances may differ, and your accountant is the right person to ask about them.