Pay Less Notice Deadlines — The 7-Day Window That Costs UK Sub-Contractors Thousands

Last year I sat opposite a sub-contractor director who had just accepted a £42,200 payment on an application he’d submitted at £56,800. His main contractor had short-paid him by £14,600 and he had assumed that was that.

It wasn’t.

The main contractor had served no valid Pay Less Notice. Under section 111 of the Housing Grants, Construction and Regeneration Act 1996, the notified sum was due in full. The director was entitled to the £14,600. He’d accepted £42,200 because he didn’t know about the seven-day window that turns the entire payment cycle on its head.

This article exists because most sub-contractor directors I meet don’t know about that window either. Once you understand it, you’ll never lose money the same way again.

If you want to skip the article: the Pay Less Notice must be served seven days before the final date for payment. Miss that window, and the notified sum is due — regardless of whether the work justified that sum.

The mechanics, briefly

Most UK construction sub-contracts run on a monthly payment cycle. The cycle has four critical dates under the Construction Act:

1. Application date — you submit your interim application for payment
2. Due date — when the obligation to pay arises (typically 14 days after the application date, but check your contract)
3. Final date for payment — when the payment must hit your bank (typically 28 days after the due date)
4. Pay Less Notice deadline — seven days before the final date for payment

The Pay Less Notice deadline is the bit most sub-contractors forget about. It’s the moment when the main contractor must formally tell you, in writing, that they intend to pay less than the notified sum — and explain why.

If they serve a valid Pay Less Notice in that window, they can reduce your payment.

If they don’t, the notified sum is due in full.

What the notified sum actually is

This is the bit that catches sub-contractors out.

The notified sum is whichever of these applies, in order:

1. The sum specified in a Payment Notice issued by the main contractor by the due date, OR
2. The sum you applied for, if the main contractor failed to serve a Payment Notice

The second one is the bit nobody talks about. If your main contractor failed to serve a formal Payment Notice within their own contractual window, your application becomes the notified sum. It doesn’t matter what they later decide to certify — without a valid Payment Notice and a valid Pay Less Notice, the sum you applied for is what they owe you.

That’s the case my £14,600 sub-contractor was in last year. The main contractor’s Quantity Surveyor had simply emailed him a spreadsheet saying “this is what we’ll certify” without serving a formal Payment Notice in the contractual format. That email wasn’t a valid notice. The pay-less window passed. The full £56,800 was due.

We recovered the £14,600. The lesson stuck.

Why main contractors miss the deadline

In fifteen years as the QS issuing pay-less notices from the main contractor side, I can tell you the four most common reasons the deadline gets missed.

Administrative bottleneck

The main contractor’s commercial team is overstretched. They’re juggling 15+ sub-contractors per project, half a dozen projects, board reports, and an Operations Director chasing them. Your pay-less notice slips through the cracks. It happens more often than you’d think.

Internal disagreement

The site team thinks the application is over-valued. The QS thinks it’s roughly fair. The Commercial Manager wants to challenge it. They debate it past the seven-day window. By the time they’ve decided to pay less, they’ve lost the right to.

Incorrect format

The notice gets sent — but it’s not signed, doesn’t quantify the deduction properly, isn’t on the right form, or doesn’t comply with the contract’s specific notice requirements. Courts have repeatedly held that substantial compliance isn’t enough for a Pay Less Notice. It must comply with the contract, or it doesn’t work.

Server-side delivery failure

The notice was sent by email to the wrong address. Or by post to the registered office instead of the contractual service address. Or to the project manager instead of the named recipient under the contract. The Pay Less Notice has strict service requirements under JCT and NEC4 — and an “I emailed it to Bob” doesn’t necessarily count.

Each of these is a real example I’ve seen on the main contractor side. Each of them, if you spot it on the sub-contractor side, is recoverable money.

What to do when a main contractor misses the deadline

This is the bit subs don’t act on enough.

Step 1 — Calculate the notified sum

Either the Payment Notice sum (if a valid one was served), or your applied sum (if none was). Write down the figure. Verify the dates of every relevant notice. This is your number.

Step 2 — Check whether a valid Pay Less Notice was served

Three tests:

1. Was anything served at all? Some main contractors just under-pay without notification.
2. Was it served in time — at least seven days before the final date for payment (or whatever your contract specifies)?
3. Did it comply with the contractual format — quantified, reasoned, signed, addressed correctly, sent via the right method?

If any of those tests fail, the Pay Less Notice is not effective and the full notified sum is due.

Step 3 — Send a formal demand letter

Within five working days of the final date for payment, send a written demand for the full notified sum. Cite section 111 of the Construction Act. Reference the absence (or invalidity) of the Pay Less Notice. Set a deadline for payment.

This single letter resolves about 60% of these cases. Main contractors with a competent QS will pay rather than argue an unwinnable position.

Step 4 — Serve a Notice of Suspension if unpaid

If the demand letter doesn’t produce payment within the stated window, serve a Notice of Intention to Suspend Performance under section 112 of the Construction Act. You give them seven days. If they still haven’t paid, you can stop work without breaching the contract.

I’ve watched a Notice of Suspension produce a £38,000 payment in three working days. The leverage is real because the main contractor’s project programme cannot afford the disruption.

Step 5 — Refer to adjudication if necessary

If all of the above fails, refer the dispute to adjudication. Under section 108 of the Construction Act, you can refer “at any time.” The adjudicator has 28 days to make a decision. Most “smash and grab” adjudications on missing Pay Less Notices result in payment within 6–10 weeks of referral.

This sounds dramatic. It isn’t. Adjudication is routine in UK construction — 2,264 referrals in the year to April 2024, the highest on record. The system exists specifically for this kind of dispute. Use it.

A one-off audit for a live project

If you’ve got a live application right now that you suspect is being short-paid, the fastest way to find out is a Live Project Audit. Upload the contract, your last two applications and any recent correspondence — you get a written report in 48 hours covering the recoverable figure, the specific demand letter to send, and the notice deadlines mapped for the rest of the project.

When this isn’t enough

A one-off audit handles a snapshot. It doesn’t handle the ongoing contractual interpretation of whether every notice is valid, or whether your applied sums are reasonable across every project. For that, the retainer is the answer.

I run a fractional QS practice specifically for UK sub-contractors. The Silver tier (£995/month + VAT) includes two to three notices or letters drafted per month — usually a Pay Less Notice challenge, a section 112 suspension letter, or an adjudication notice. The Gold tier (£1,995/month + VAT) includes adjudication evidence pack preparation as standard.

My first conversation is free. Thirty minutes. If you’ve got a live dispute, bring the application numbers, the Payment Notice (or evidence none was served), the contract, and a calendar. I’ll tell you what I see in the first five minutes.

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The legal bit, briefly

The Construction Act references in this article are accurate as at 3 June 2026:

• Section 110A — payment notice requirements
• Section 111 — pay less notice requirements
• Section 112 — right to suspend performance
• Section 108 — adjudication rights

This article is general guidance, not legal advice. For specific disputes worth more than £20,000 or where the contract is in any way contested, we always recommend a construction solicitor or chartered Quantity Surveyor be involved in the response. Even the cheapest retainer tier (£495/mo + VAT) gets you a second commercial opinion before you act.

The single most important thing is that you act within five working days of spotting the breach. The longer you wait, the more it looks like acquiescence, and the harder it becomes to recover the full sum.