Most invoicing tools Canadian contractors use were built for the US market or for general small business. They produce invoices that look fine but do not qualify as a proper invoice under the Ontario Construction Act. A proper invoice is the trigger for the 28-day prompt-payment clock; if your invoice is missing a required field, the payer can issue a deficiency notice and the clock never starts. Construction invoicing in Canada is a compliance task, not just a billing task.
Why tracking it by hand goes wrong
- The period of work, a date range and not just an invoice date, is the most commonly missing field. Without it, your invoice is not a proper invoice.
- A contract reference is required. The customer's name alone is not enough; you need the job address, contract number, or purchase order.
- Your GST/HST registration number must appear, with the tax shown or stated as included, or your customer cannot claim the input tax credit. That is a CRA rule on top of the Construction Act fields.
- Tax is not one rate. HST, GST, PST, and QST differ by province, and QST is calculated on the pre-GST base in Quebec.
- A non-qualifying invoice gives you no 28-day payment protection at all, even though it looks like a normal invoice.
How Markup handles it
Proper invoices by default
Every invoice includes the section 6.1 fields, so it meets the Construction Act's proper-invoice requirements without manual template editing. The 28-day clock then runs from the day your customer receives it.
Province-aware tax engine
The correct GST, HST, PST, or QST is applied automatically for all 13 provinces and territories, including QST on the pre-GST base.
Open and payment tracking
The 28-day clock runs from the day your customer receives the invoice. Markup shows you when they open it, flags it if they have not opened it after 7 days, and sends reminders 7 and 14 days after the due date.
Quote to invoice
Convert an accepted quote into a linked invoice without re-keying line items or tax.
Frequently asked questions
What is a proper invoice under the Construction Act?
A proper invoice is an invoice that meets section 6.1 of the Ontario Construction Act. It must include specific fields, including the period of work, a contract reference, and payment-recipient details. Only a proper invoice starts the 28-day prompt-payment clock.
What makes construction invoicing in Canada different?
It is a compliance task. Under prompt-payment rules, the invoice itself is the legal trigger for payment deadlines. A generic invoice that misses a required field gives you no payment protection, so the format matters as much as the amount.
Do QuickBooks, FreshBooks, or Wave create proper invoices?
No. General invoicing and accounting tools use generic templates without the section 6.1 fields, so they do not start the 28-day clock. Markup builds those fields in by default.
Is Markup's construction invoicing software free?
Yes to start. The free plan includes province-aware proper invoices and the client portal with a small limit: 2 invoices, 2 quotes, 2 clients and 2 projects at a time. Quote-to-invoice and higher limits are on the paid plans, and every new account gets a 28-day free trial of Plus with no card required.
This page is general information only and does not constitute tax or legal advice. CRA rules and filing thresholds can change. For advice specific to your situation, consult a licensed professional.