An application has landed that's obviously wrong and the window is closing

An application arrives claiming a figure nobody on your side believes: a variation counted twice, retention ignored, work valued that has not been done. Because the error is obvious, it does not feel urgent. Everyone assumes a figure that wrong cannot possibly become payable, so the reply joins the queue behind the rest of the month.

The Construction Act has no exception for obviously wrong. If no valid Payment Notice or Pay Less Notice goes out in time, the applied sum can become the Notified Sum, the figure that must be paid in full, however inflated everyone agrees it is. Whole adjudications are won on exactly this: not whether the figure was right, but whether the paperwork answering it was served in time and in valid form.

An email saying the application is nonsense is not a notice. What stops the mistake becoming payable is a valid notice: the sum you say is due, the basis it is calculated on, served by the right party to the right recipient inside the deadline. The clock does not pause while the right words are found.