Contractual compliance and variations: Why shared assumptions don't guarantee payment

A recent decision of the UK Privy Council reminds Australian construction participants that strict compliance with contractual variation procedures remains critical, even where additional work has plainly been performed and even where the superintendent appears to be on board.

In Uniform Building Contractors Ltd v The Water and Sewerage Authority of Trinidad and Tobago [2026] UKPC 2, the Privy Council overturned a substantial award in favour of a contractor, holding that none of the claimed items were variations and that, in any event, the contractor had failed to comply with mandatory contractual procedures for claiming additional payment.

Although the decision arises out of Trinidad and Tobago, it will feel very familiar to Australian contractors, principals and superintendents, particularly those working under FIDIC-style or Australian Standard contracts.