We use cookies to keep you signed in and to see what's working and what breaks. No advertising cookies, nothing sold. Details in our Cookie Policy.

Construction guides for Ontario contractors

101 guides written against Ontario rules, not translated from somewhere else. Every one of them ends somewhere you can act.

Start with a subject

Count it instead of reading about it

Hourly rate calculator
Overhead, billable days and the wage you want in. The hourly rate that pays for all three.
HST on holdback calculator
You charge HST on the full value of the work, including the tenth being held. You do not remit all of it yet. Enter the job and get both numbers, and the date the rest falls due.
Do you have to charge HST yet?
The small supplier threshold has two tests. The one that catches a contractor is the single quarter test, and it has no grace month. Enter your quarters and see which one bites first.
Markup and margin calculator
Add twenty percent to your costs and you keep sixteen point seven. Enter one job and see the price, the profit, both percentages, and what the mix-up is worth in dollars.
Ontario filing deadline calendar
Every date a contractor owes the CRA and WSIB, counted from your own year end. Including the T5018, which is the one that surprises people.
Ontario lien deadline calculator
Last day on site and contract date in. Preservation, perfection and the annual holdback dates out, counted with the periods in the Construction Act.
Ontario prompt payment calculator
One date in: the day you gave them a proper invoice. Out comes the day they have to pay, the day they had to dispute it, and the day you owe your own subs whether or not you were paid.
WSIB premium calculator
What WSIB costs you this year on your own crew, and what it can cost you a second time on the subcontractors you never collected a clearance certificate from.

How to run the business

Before you qualify

After you qualify

The dates that cost Ontario contractors money

One email a month. What is due at CRA and WSIB, the Construction Act clocks that started running on your last invoice, and every new guide the day it goes up.

Your lien clocks, counted for you. Preserve is 60 days under section 31 and perfect is a further 90 under section 36, and neither one can be extended once it has gone.
The remittance and filing dates for the month ahead, so HST and WSIB stop arriving as a surprise and the T5018 stops being a January problem.
Every new guide the day it goes up. 101 are live for Ontario right now, the most recent being "Where work is starting" on 19 August 2026.

Read it, or run it

Every guide here describes something the platform does. Open a working business and watch it happen instead.

Open a working business