Work out your four
payment dates.
Put in the end of the valuation period and the periods from your contract. It returns the due date, the payment notice deadline, the pay less deadline and the final date for payment, with the rule behind each one. Nothing is sent anywhere.
How to read the result
The four dates run in a fixed order and each one does a different job. The due date is when the payment becomes due and it starts the clock; it is not when you get paid. The payment notice deadline is the last day the payer can state the sum it considers due, which fixes the notified sum. The pay less notice deadline is the last day the payer can serve notice that it intends to pay less than that sum. The final date for payment is when the money has to be with you.
The consequence of the third date is the one worth internalising. If no valid pay less notice is served in time, the notified sum falls due in full on the final date, whatever the payer thinks the work was worth. A pay less notice that arrives a day after the deadline is not a weak notice. It is not a notice at all.
Why the defaults are what they are
The Scheme for Construction Contracts supplies terms where a construction contract fails to provide compliant ones. Its defaults are seven days from the end of the relevant period to the due date, seventeen days from the due date to the final date for payment, a payment notice not later than five days after the due date, and a pay less notice not later than seven days before the final date.
Those are the figures this tool starts with, and they are the fallback the industry is measured against. They are not what your contract says unless your contract is silent or non-compliant. JCT and NEC subcontracts each run their own timetable, and a bespoke amendment can move the dates again, which is why the second option exists.
What this does not do
It counts calendar days, because that is how the Scheme counts them. Where your contract counts business days, or excludes a Christmas shutdown, enter the periods your contract actually uses rather than the defaults.
It also assumes the Act applies to your contract at all. It does not where your customer is a residential occupier, and it may not where the work is the assembly or installation of plant on certain process sites. Both exclusions are explained in what the Construction Act actually gives you.
This is a calculator, not advice on your contract. If a payment is already in dispute, the dates matter more than anything on this page and they are worth checking against the document itself.