ABSTRACT
'Provisional sums' can be a source of problems and disputes for the unwary subbie. A provisional sum is an allowance or best guess, inserted into enquiry documents for a specific element of the works that is not yet defined in enough detail for tenderers to accurately price. However, some subbies will also include their own provisional sums in their tender. Provisional sums are provided for in different ways in different forms of contract, and some forms of contract can be a little vague about how provisional sums should be handled, particularly regarding adjustments to the programme and associated preliminaries. As provisional sums are replaced by valuations of the work actually done, the contract sum may increase or decrease. In addition, the actual works that are undertaken may affect one programming, planning and recovery of preliminaries.
