Payment Certificate

A payment certificate is a formal document issued by a contract administrator, architect, or quantity surveyor on a construction project, confirming the value of work completed up to a specific date and authorizing the employer to release a corresponding payment to the contractor. It provides a verified record of progress and is the primary mechanism through which contractors receive payment on most standard-form UK construction contracts, including JCT and NEC forms. Payment certificates are not a legal requirement but are universal in practice because they create a structured, documented payment process agreed by all parties.

Types of Payment Certificate

There are three main types of payment certificate used across a construction project lifecycle.

Interim certificates are issued periodically - typically monthly - and cover the cumulative value of work completed to the valuation date, minus any previous payments and retention held. They allow regular cash flow to the contractor as work progresses.

The certificate of practical completion signals that the works are substantially finished and meet the agreed standard, with only minor defects remaining. It triggers the release of the first portion of retention held and marks the start of the defects liability period.

The final certificate is issued once the defects liability period has elapsed and all identified defects have been remedied. It confirms the total contractual sum due and triggers the release of remaining retention.

How a Payment Certificate Fits Into the Payment Cycle

Under JCT Standard Building Contract terms, a contractor submits a payment application to the quantity surveyor before the valuation date, setting out the sum they consider due and the basis for that calculation. The contract administrator must then issue an interim certificate within five calendar days of the due date, as required by the Housing Grants, Construction and Regeneration Act 1996.

If the employer intends to pay less than the certified amount, they must issue a pay less notice within the contractually specified period before the final date for payment. If no pay less notice is issued, the full certified sum becomes due regardless of any dispute. This mechanism is central to the UK construction payment regime and is designed to maintain contractor cash flow throughout the project.

Disputed payment certificates are one of the most common triggers for formal disputes on UK construction projects. The Housing Grants, Construction and Regeneration Act 1996 gives any party to a construction contract the right to refer a payment dispute to adjudication - a statutory 28-day process that produces a binding interim decision.