Agent or principal: the contract sets your HST base
Buying media as agent for a disclosed client means the media vendor is really supplying your client. The spend passes through you, and you charge 13% HST only on your fee or commission. Buying as principal, contracting in your own name and rebilling, makes the whole rebilled amount your own taxable supply: HST on the gross, with input tax credits back on the media purchase.
The CRA decides which one you are from the agreements and the conduct, not from the label on the invoice. Who is liable to the vendor if the client never pays? Whose name is on the insertion order? Who wears a mispriced buy? If those answers say principal, invoicing like an agent is an assessment waiting for a reviewer.
| Question | Billing as agent | Billing as principal |
|---|---|---|
| HST is charged on | Your fee or commission only | The full rebilled amount |
| ITCs on the media cost | Your client's to claim, not yours | Yours to claim |
| Cash flow | You remit tax on the fee | You remit on gross, recover on the buy |
| Paperwork that must exist | Agency authority and disclosed-client billing | Your own vendor contracts and resale invoices |
For registered business clients the two routes often net out, which is how the sloppiness survives. It stops being harmless when the client cannot recover HST in full: clinics, financial services firms, charities and public bodies genuinely pay more under principal billing. Principal billing also pulls the gross spend into your own taxable-supplies totals, which can push the agency from annual into quarterly or monthly HST filing.
Thirteen percent is not the only rate on your invoices
For services, the GST/HST rate generally follows the client's address, not yours. An agency in Mississauga charges 13% to an Ontario client, 5% GST to a Calgary head office, and 15% to a client in Newfoundland and Labrador. The place-of-supply mapping is a one-time fix in your invoicing template that prevents years of quiet under- or over-charging, and we set it per client, not per project.
Services billed to non-resident clients can be zero-rated under Canadian HST rules, but the conditions are specific and worth professional attention before anyone stops charging tax. We flag those files and document the basis instead of guessing.
The agency T2, on an accrual footing
The corporate return starts from books that already treat retainers and project work properly, so the filing job is applying the right mechanics: the reserve on retainer amounts not yet earned, freelancer costs deducted in the year the work happened, and the small business deduction holding the first $500,000 of active profit to roughly 12.2% combined in Ontario. That work is Corporate Tax Filing, quoted in writing after a free discovery call, never billed by the surprise hour.
Two calendar decisions matter more than agencies expect. A year-end set away from your pitch-heavy season keeps the T2 a quiet event; the return is due six months after that date and the balance for most small CCPCs three months after it. And instalments get reset immediately after each filing, so a record year does not set payments that strangle the leaner year behind it.
February is slip month
T4s for staff, T4A slips for the freelance bench, T5s if the owners took dividends: all due the last day of February. The run is mechanical when freelancer payments were coded through the year and miserable when they were not. Who belongs on a T4A in the first place, and how to keep contractors from drifting into employee territory, is a planning question, and we give it a full treatment on our agency tax planning page.
HST reviews love rebilled media
Agencies attract a particular letter: a pre- or post-assessment HST review triggered by large input tax credits in a heavy media quarter. The answer is the contracts, the insertion orders and a clean ITC listing, which is exactly what our filing file already holds. CRA Audit & Review Support responds from working papers rather than reconstructions, and most of these reviews end at the first reply.
Source: CRA — Which GST/HST rate to charge.
