Provisional Sum
An allowance included in the contract for work that cannot be fully defined at tender — carried as a lump sum, then expended, omitted or adjusted when the work is properly instructed and valued.
A provisional sum is not a price. It is a placeholder, and its inclusion in the contract sum does not mean the work will cost that. When the scope is defined, the sum is expended against the actual valuation and the difference adjusts the contract price in either direction.
The discipline is to instruct it properly. A provisional sum that is quietly consumed without a formal instruction, with the work simply carried out and paid for, produces a contract sum nobody can reconcile — and a final account in which neither side can explain where the money went.
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