How long do I have to issue a demand letter after a Construction Act deadline passes?
By George Kershaw, Founder, ContraUpdated
The Construction Act sets no fixed deadline for issuing your demand for the Notified Sum - the right does not expire on a set date. But you should act immediately: the sooner you demand, and if needed refer to adjudication, the sooner you are paid and the lower the risk the main contractor's finances fail first. Ordinary contractual limitation periods still apply as the long-stop.
Key takeaways
- The Construction Act sets no fixed deadline for your demand - the right does not expire on a set date.
- Act immediately: insolvency risk, not the law, is the real clock.
- General limitation applies as the long-stop: commonly six years for a simple contract, twelve for a deed.
- A dated, written demand stating the Notified Sum and the missed notice is your evidence.
No statutory deadline for the demand
The Act imposes deadlines on the main contractor's notices, not on your demand. Once a Notified Sum has crystallised, the debt stands - there is no short window in which you must act or lose it. You can demand it after the final date for payment has passed.
Why speed still matters
The practical clock is harsher than the legal one. UK construction days-sales-outstanding runs at 65 to 80 days, and 3,827 UK construction firms went insolvent in the twelve months to March 2026, with specialist subcontractors more than half of the monthly count. A crystallised entitlement is worth little against an insolvent main contractor, so the money you are owed erodes the longer you wait.
What the demand should contain
- The Notified Sum and how it is made up.
- The missed Payment Notice or Pay Less Notice, and the deadline that passed.
- The final date for payment that has now elapsed.
- A clear demand for payment, dated and in writing so it stands as evidence.
Limitation is the long-stop
General limitation periods still apply to the underlying debt - commonly six years for a simple contract and twelve for a contract executed as a deed. These are outer limits, not targets; take advice on your contract. In practice, insolvency risk will force your hand long before limitation does.
Where Contra fits
The Clock™ flags every deadline before it lapses and the moment it does, and Crystallised Entitlement™ drafts the demand from The Record™ the instant the entitlement is yours - so nothing sits waiting while the main contractor's position weakens.
This guide is general information on UK construction payment law, not legal advice. Payment terms vary by contract; take advice on your specific position.
About the author
George Kershaw · Founder, Contra
George Kershaw is the founder of Contra, which builds Construction Act payment and deadline tracking for UK specialist subcontractors. He writes on subcontractor payment rights, the Housing Grants, Construction and Regeneration Act 1996, and construction adjudication.
Sources
Frequently asked
Is there a time limit to demand a Notified Sum?
The Construction Act sets no fixed deadline for the demand. General contract limitation periods apply as a long-stop - commonly six years for a simple contract, twelve for a deed.
What should a demand letter contain?
The Notified Sum, the notice the main contractor missed, the final date for payment that has passed, and a clear, dated written demand for payment.
Does waiting weaken my claim?
Not in law, until limitation. In practice, delay raises the risk the main contractor becomes insolvent before you are paid, which is the real reason to act at once.
Related guides
Stop tracking deadlines in a spreadsheet.
Contra tracks every Application for Payment and every Construction Act deadline, and drafts the demand letter the moment one lapses. Early access is opening to UK specialist subcontractors.