Why this matters

A provisional sum holds money for work that is not fully defined when the contract is priced. It can protect programme flexibility, but it also moves scope and price decisions into the construction period.

Before work starts

The project team should identify what remains unknown, who will complete the design and how quotations or subcontractors will be selected. Allowances need realistic bases and clear exclusions.

What to watch on site

Before spending the sum, issue a documented instruction with scope, price build-up, programme effect and approval. Track the original allowance, committed amount and forecast balance separately.

Handover and the lasting record

Final accounts should show how each provisional sum was resolved. Unused allowances should not quietly migrate to unrelated work without the contract’s approval process.

Editorial note

This practical article explains a project-control issue using the official reference listed below. Requirements depend on the contract, site, approving authority and current law; the responsible registered professional should confirm the project-specific position.

What we will track next

The strongest follow-up to Provisional sums: the budget line that still needs a procurement plan is an auditable chain from decision to outcome. Scope, authority, quotation, approval, delivery and payment should agree, with changes recorded while the work is active.

Commercial records are project controls, not end-of-job paperwork. A current programme, cost forecast, instruction register and payment history let the team address risk early and give reviewers evidence for the final account.

Sources