ChD 20 November 1991. In 1989 A were engaged in constructing a number of filling stations for P and entered into subcontracts with H. These referred to a head contract between A and P and contained the clause that `A agrees to pay all stage payments in accordance with the timing specified in the P agreement and a balancing payment (if any) on the same day as specified in the P agreement, retentions also being dealt with in the same manner as the P agreement`. The main contract contained a provision which permitted P to pay the works price to A against monthly certificates. On 4 September a joint administrative receiver was appointed to H who commenced proceedings to recover money due under interim certificates. A liquidator was appointed in March 1991. The claim was on three certificates. A claimed entitlement to set-off sums for overpayment in relation to two of the contracts. A argued that they were entitled to equity set-off sums due under other contracts, this failed on the groun