FIDIC glossary · Payments
Provisional Sum
Provisional Sum
In short
A sum included in the price for work/supply to be defined later; spent on the Engineer’s instruction.
What is a Provisional Sum?
A Provisional Sum is an amount included in the Contract Price for work, supply or services that are not defined precisely enough at signature to be priced. It is an honest device: it admits that part of the scope is still unclear rather than pretending otherwise.
The mechanics are simple and frequently broken. The sum sits inside the Accepted Contract Amount but **does not belong to the Contractor**. It can only be spent on the Engineer's instruction — in whole, in part, or not at all. Anything unspent is deducted at final account.
The part that is spent is valued as a Variation under Clause 13, plus the agreed percentage for the Contractor's overhead and profit where the sum is delivered through a subcontract or purchase.
The practical trap: a Provisional Sum gives the Contractor no right to the work and no guarantee of volume. Planning workload or margin around provisional sums is an expensive mistake at close-out.
The mirror trap for the Employer: too large a share of provisional sums means the contract price is not actually fixed, and the tender compared bids that were never comparable.
Where it sits in the contract
Related terms
Need this read against your own contract?
This explains how the mechanism works in the standard form. How it works in your contract, after the Particular Conditions, is a separate question.
Talk to an expert →A reference explanation of the FIDIC standard conditions. Not legal advice, and not a reproduction of the FIDIC books.