Anyone who has provided services or materials in the construction industry has likely run into the issue of non-payment of their invoices. But how do you determine when the limitation period begins to run for an unpaid invoice, and in turn, the deadline for when a lawsuit must be commenced? The recent case of 1838120 Ontario Inc. v. Township of East Zorra-Tavistock, 2021 ONSC 3341, is of assistance in answering these questions.