How do JCT Pay Less Notices and Payment Notices work?

If no certificate is issued in time, the Contractor's Interim Payment Notice stands in. This follows the Housing Grants, Construction and Regeneration Act 1996. Section 110A requires a Payment Notice stating the sum considered due and how it was worked out. Section 110B lets the payee give its own notice when the payer's is not given. Section 111 requires the notified sum to be paid by the final date for payment, unless a Pay Less Notice is given in time. In the JCT Standard Building Contract With Quantities 2016 (SBC/Q), the interim payment rules are in section 4. The Architect/Contract Administrator's Interim Certificate, issued no later than 5 days after the due date, is the Payment Notice. If no certificate is issued in that time, the Contractor's interim payment application, if it made one, becomes its Interim Payment Notice. If it made none, it can give an Interim Payment Notice at any time after that period. The final date for payment then moves back to reflect how late it was given. The Employer, or someone it authorises, gives any Pay Less Notice no later than 5 days before the final date for payment. It must state the sum the Employer considers due at the date of the notice and how that was worked out. Three things go wrong again and again. An Interim Certificate is issued late and treated as if it still fixed the sum. A Pay Less Notice arrives before the final date but outside its own window. Or a certificate gives a figure with no basis, which invites a challenge to the notice rather than to the valuation. The JCT sub-contracts follow the same pattern one tier down. Your main contractor gives the Payment Notice and any Pay Less Notice to you, so check the dates in your own sub-contract, not the main contract.