Source: https://www.quantsurv.com/library/glossary/provisional-sum
Content format: Markdown version of the public page.
Content reviewed: 2026-10-12

# Provisional sum

An allowance for work not sufficiently defined for a firm price when the contract documents are prepared.

by [Jack Butler-Kettle](<https://www.quantsurv.com/about#jack-butler-kettle>) · About 1 min readShare

## Further detail

Read this alongside [NRM 2: Detailed measurement for building works](<https://www.rics.org/content/dam/ricsglobal/documents/standards/NRM-2_Oct2022_Update.pdf>).

A provisional sum identifies work whose scope or details remain uncertain at pricing. Check what the allowance covers and the procedure for instruction, valuation and adjustment. Under the applicable measurement rules, defined and undefined provisional sums have different information requirements. An allowance is not automatically an agreed price for whatever work is later instructed.

Read the allowance with the specification, measurement rules and contract. Make its scope and omissions visible in the [tender comparison](<https://www.quantsurv.com/library/comparing-construction-tenders>). Our [quantity surveying services](<https://www.quantsurv.com/quantity-surveying>) include checking allowances and valuing instructed work against the relevant pricing documents.

## Sources

1.  [NRM 2: Detailed measurement for building works, UK 2nd edition, October 2021 (reissued October 2022 as RICS practice information)](<https://www.rics.org/content/dam/ricsglobal/documents/standards/NRM-2_Oct2022_Update.pdf>). RICS.

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