Construction Act
The client is deducting for defects. Can they just do that?
The payment lands short, and attached is a list: scratched glass, a door that sticks, paint. Some of it may even be fair. But fair or not, a deduction has rules, about notice, about timing, and about the number itself, and most defect deductions fail at least one of them.
QScope Team·1 May 2026·5 min read
Separate two questions the client has run together: is the work defective, and were they entitled to deduct for it this month. The second has a yes-or-no answer you can check today.
The paperwork question: was there a notice?
On jobs the Construction Act covers, the sum in play is the notified sum, and paying less than it requires a pay less notice, served in time, stating the sum considered due and the basis on which it is calculated (section 111). That has consequences people miss:
- A snag list is not a pay less notice. It names problems; it does not state a sum or a calculation.
- An email saying “we are unhappy and holding money” is not one either.
- A late notice is no notice. The window is fixed by the contract or the Scheme, and it closes.
No valid notice means the notified sum was payable in full by the final date, defects or no defects, and the shortfall is simply a late payment. The defects discussion still happens, but it happens next month or in the final account, not by helping themselves to this one. The full mechanics are on the pay less notice page.
The money question: is the number real?
Where a notice does exist, look at the sum. The measure of a defect claim is in principle the reasonable cost of putting the work right, not a number that expresses how annoyed somebody is. A £4,000 deduction for a sticking door is not a valuation, it is a position. Ask for the build-up in writing: item by item, costed. A client who cannot produce one has told you something useful about how the argument ends.
Genuine defects deserve a different letter
If some items on the list are real, say so, and offer dates to attend. It costs you a day of labour, it removes those items from the argument, and it puts you on the right side of every later reading of the file. The fight worth having is over the invented items and the invented numbers, not over a cracked tile you would have fixed anyway. On what separates a snag from a defect, see snagging and defects.
On a job for someone living in the house
The notice machinery above belongs to the Act, and the Act does not apply to a contract with a residential occupier (section 106). A homeowner who pays short over defects is not breaking a notice rule, because there is none. What survives is the money question, the deduction still has to reflect a real, costed loss, and the practical ladder: itemised response, offer to fix, then a letter before action for the balance, through the county court rather than adjudication.
What to do this week
1. Check the notice against the calendar: was anything served, was it in time, does it state a sum and a basis? Ten minutes, and it often ends the argument.
2. Answer the list in writing, item by item: agreed and will fix on [date]; not a defect, because; not costed, please provide the build-up.
3. Chase the shortfall as a late payment where the notice fails, with the escalation the rest of this series describes: interest, adjudication under section 108 on business jobs, the court route on domestic ones.
Where the information stops
Whether a particular item is a defect or a design choice, and what a reasonable repair cost is on your facts, are exactly the questions experts and adjudicators get paid to answer. When the deduction is large, an hour with a construction solicitor before you reply in writing is cheap insurance, because your first letter is the one every later reader sees.