Private Customers | What is a Provisional Sum?

A provisional sum is an allowance (or best guess), usually estimated by an estimator or quantity surveyor, that is inserted into quotations for a specific element of the works that is not yet detailed enough to give an accurate price.

Provisional sums are replaced by work actually done as the project progresses, the contract sum (sum originally shown on the quotation) may increase or decrease. The original time scale for the project may also change.