What are the prompt payment rules under Ontario's Construction Act?

The Construction Act's prompt payment regime sets out fixed timelines for paying valid invoices on a construction project, aiming to keep money flowing down the contracting chain instead of subcontractors and suppliers waiting indefinitely while payment disputes higher up the chain drag on. An owner who receives a proper invoice from a contractor must pay it, or deliver a valid notice of non-payment setting out the specific reasons for withholding, within the timelines the Act sets, and a similar cascading obligation and timeline applies as payment (or a proper non-payment notice) flows down from contractors to subcontractors.

If a party doesn't pay a properly invoiced amount and doesn't deliver a valid non-payment notice within the required time, they generally lose the ability to dispute that specific amount later and simply owe it. Because a notice of non-payment has to meet specific content requirements to be valid, an owner or contractor who wants to dispute an invoice needs to respond properly and on time, not just informally push back or stay silent. These prompt payment obligations work together with the Construction Act's separate adjudication process, which gives a fast, interim-binding way to resolve a payment dispute without waiting for a full lawsuit.