In a recent case,(1) an architect issued a 'final certificate'. The contractor sent a letter claiming £115,450.50 and followed up with an adjudication. The adjudicator decided that the final certificate was ineffective and the contractor's letter was not a valid payment notice, as it was based on the invalid final certificate and did not clarify that it was a notice and issued under the relevant clause. The contractor sent another letter seeking payment, describing it as a notice pursuant to the same clause, and followed up with a second adjudication, in which the employer (who did not serve a pay less notice) declined to participate, saying that it was the same, or substantially the same, dispute as had been decided in the first adjudication. But was it?

According to case law, whether one dispute is substantially the same as another is a question of fact and degree. In this case the Court of Appeal decided that the disputes were not substantially the same. The second adjudicator recognised that both parties were bound by the first adjudicator's finding that the final certificate and the contractor's first claim letter were ineffective, and was being asked to decide whether a different notice served four months later had different consequences. The contractor was not making good a shortcoming in the earlier letter; it was approaching its claim through a new and different route. It was the new notice – and only the new notice – which founded the contractor's entitlement to be paid.

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(1) Brown v Complete Buildings Solutions Ltd [2016] EWCA Civ 1.

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