The short version
A Default Payment Notice is a formal document that forces a main contractor to pay you the full amount of your invoice. It works because of a strict rule in UK law: if the contractor doesn't issue their own Payment Notice within 5 days of the Payment Due Date, they lose the right to dispute your invoice amount. The full sum becomes payable immediately.
How it works — step by step
You submit your invoice
You send an invoice or application for payment to the main contractor. This starts the clock.
The Payment Due Date arrives
Under the Scheme for Construction Contracts, payment is due 30 days after your invoice date (or whatever your contract states). If the due date falls on a weekend or bank holiday, it moves to the next business day.
The 5-day window opens
The contractor has 5 calendar days after the Payment Due Date to issue a Payment Notice — a formal document stating how much they intend to pay and why. This is their only chance to challenge the amount.
They miss the deadline
If those 5 days pass without a Payment Notice from the contractor, they’ve blown it. They can no longer dispute the amount. Your full invoice becomes the “notified sum.”
You issue a Default Payment Notice
Under Section 110B of the Construction Act, you issue a formal Default Payment Notice stating the notified sum (your full invoice amount). This must be paid by the Final Date for Payment — typically 17 days after the due date.
What the law actually says
Section 110Bof the Housing Grants, Construction and Regeneration Act 1996 (as amended by the Local Democracy, Economic Development and Construction Act 2009) states that where a payer fails to give a payment notice under section 110A(2), the payee may give a notice to the payer of the sum that the payee considers to be due at the payment due date. That sum then becomes the "notified sum" — payable in full.
The payer's only defence is to issue a valid Pay Less Notice before the prescribed period. If they miss both the Payment Notice and the Pay Less Notice deadlines, the full amount is due with no right of set-off.
If they still don't pay
Suspend work (Section 112)
Give 7 days’ written notice, then stop all work. You’re entitled to a reasonable extension of time and any additional costs caused by the suspension.
Refer to adjudication (Section 108)
An adjudicator makes a binding decision within 28 days. This is fast, relatively cheap, and the contractor must comply immediately — they can only challenge it later in court.
Claim statutory interest
Under the Late Payment of Commercial Debts (Interest) Act 1998, you can claim interest at 8% above the Bank of England base rate, plus a fixed compensation amount of £40–£100.
Common questions
Do I need a written contract?
No. If there’s no written contract, the Scheme for Construction Contracts applies automatically. Payment becomes due 30 days after your invoice date.
Does this apply to residential work?
The Act applies to most construction contracts, but there are exceptions for residential occupiers — i.e., homeowners commissioning work on their own home. If you’re a subcontractor working for a main contractor on a residential project, you ARE covered.
Can they send a Pay Less Notice after the deadline?
No. A Pay Less Notice must be served before the prescribed period (7 days before the Final Date for Payment). After that, it’s too late.
How do I send the notice?
Email with read receipt, recorded delivery post, or hand delivery. Keep proof that it was sent and received. The more formal the better.