The arguments considered
47 The construction advanced on behalf of the defendant is unsound.
48 First, even if a "claimant", as defined by s 13(1), delays in serving a payment claim beyond a time which is ten business days before the contractual due date in which the "respondent" becomes liable to pay the claimed amount, as a matter of language there is no strain in concluding that, if no payment schedule is provided by the respondent in time, the respondent "becomes" liable to pay at a passed date. If strictness of construction, which the defendant's approach calls for, is to be applied, that approach is not strict enough. It fastens on the contrast between the present tense of "becomes" and the occurrence of liability to pay in the past. But if the defendant's construction were correct, the word "becomes" should have been "will become" or, to cover the possibility of a payment claim served precisely ten business days before the due date for the progress payment, "will become or becomes". Since that language was not used, there is no strain in construing "becomes" to mean "became, becomes or will become".
49 Secondly, whether or not the provisions creating a strict regime where claimants are not paid, and the provisions requiring adjudication to be prosecuted expeditiously, point towards the defendant's construction, there is no express language supporting it. The conclusion that the significant statutory rights conferred are only capable of being availed of by claimants within the narrow time period contended for by the defendant could only be drawn if the language used were clear. It is certainly possible for statutory rights of a valuable kind to be granted on the strictest temporal conditions, but in the absence of clear language one would not lightly arrive at a construction having the result that they could be lost by a short delay, whether that delay was the result of intentional behaviour by the claimant, or oversight, or accident, or some intervening and overriding event. And the clear language necessary is language which one would expect to exist not in s 14, dealing with responses to payment schedules, but in s 13, dealing with the conditions which must be satisfied by payment claims. Section 13(2) states formal requirements for payment claims. If there were to be a substantive strict requirement in relation to time, one would expect to find it there. It is not there.
50 Thirdly, there is nothing in s 13 which suggests that a payment claim cannot include entitlements to more than one progress payment. If it can, that points significantly against any time limitation barring payment claims for any progress payment but the last being inferred from s 14(4) and from other aspects of the statutory scheme.
51 Fourthly, the two limbs of that part of the definition of "reference date" appearing in s 8(2)(a) reveal a legislative intention to permit payment claims to be made either by reference to a contractual date for making a claim (ie under clause 42.1) or by reference to a contractual date by reference to which the amount of the progress payment is to be calculated (ie taking into account clause 42.2). An entitlement to a progress payment resting on recourse to the latter date is not precluded by the fact that there was an earlier entitlement to a progress payment resting on a recourse to the former date. And if recourse is had to the latter date, the statutory entitlement to a progress payment created by s 8(1) includes a entitlement to sums owing from periods anterior to the month at the end of which the latest contractual claim is made. While clause 42.1 obliges the Subcontractor to make a claim each month, and to include in it "all amounts then due", clause 42.2 makes it clear that the amounts due include those referable to earlier months, because the "amount due" is "the value of the work … in performance of the Subcontract to that time", not just in that month. While clause 42.1 compels monthly claims, s 8 contemplates entitlements to progress payments arising not only by reason of the dates for making claims under clause 42.1, but by reason of a date by reference to which the amount of the progress payment is to be calculated under clause 42.2, and the latter date includes periods which may be greater than the preceding month.
52 Finally, the defendant's arguments based on the speedy system of adjudication, the importance of inspection, and the need to arrive at a construction preserving the Main Contractor's right to inspect are very substantially weakened by the Main Contractor's rights under clause 31.1 and clause 31.2.
53 Accordingly, on the true construction of the Building and Construction Industry Security of Payment Act 1999 it is permissible for a person entitled to a progress payment under a construction contract to serve a payment claim on the person who under the contract is liable to make the payment even though the claim relates to work done in periods prior to the month in which the payment claim is served. Hence the defendant's payment claim was not invalid.