[2003] EWCA Civ 1563, 12 November 2003. The appellant defendents (J) were having building works on their cottage by the claimants builders (R). J had engaged an architect and the contract was a ASI Standard Form. R was being paid on an interim basis pursuant to the scheme of the contract. Under the contract the architect was to issue an interim certificate, based on a bill presented by R. J refused to make full payment on the presentation of the seventh interim certificate, contending that it included items already paid or incorrectly charged as extras and snagging works. J did not serve a notice of intention to withhold payment in accordance with Housing Grants, Construction and Regeneration Act 1996 s111. R sued J, but J argued they could not be sued for what was not owed. "Held" CA ruled the certificate determined the sum due, not the actual work done. J were obliged to pay the amount certified having not served a withholding notice. View judgment at www.courtservice.gov.uk.