When does HST become payable on a holdback amount in an Ontario construction contract?

Construction contracts get special timing treatment under the Excise Tax Act for the holdback portion of a progress payment, the amount contractors are typically required to retain under construction lien legislation until the lien period expires. Rather than HST on the full progress billing, including the holdback, becoming payable right away the way it would on an ordinary invoice, the tax on the holdback portion is generally treated as becoming payable at the earlier of the day the holdback is actually paid out and the day it becomes payable under the contract, commonly once the applicable lien period has run.

This means a contractor generally doesn't have to remit HST on the holdback amount up front, out of pocket, before they've actually received it or become entitled to it, which recognizes that holdbacks can sit unpaid for months as a matter of standard construction practice. It also means the recipient's ability to claim an input tax credit on that same holdback portion is generally tied to that same later timing, not to the original invoice date.

Because holdback timing rules interact with contract terms and lien legislation, and getting the calculation wrong can affect both the payer's and the recipient's HST filings, confirm how your specific contract's holdback should be treated with an accountant familiar with construction HST rules.