Can the client charge me for finishing late?

Liquidated damages (LADs, or liquidated and ascertained damages) are a rate written into the contract particulars, so much per week or day of delay past the completion date, agreed in advance as the price of lateness. Their point is certainty in both directions: the client does not have to prove what your delay actually cost them, and you know your exposure to the pound before you sign. If your particulars name a rate and the job ran late, then yes, in principle, they can charge it.

In practice, check three things before conceding a penny, in this order:

Check one: did they follow their own machinery?

Standard forms hang conditions on the deduction. On several, a certificate of non-completion must be issued first, formally recording that the works were not complete by the date, and on many, a written notice of intention to deduct as well; the certificate-first rule has its own page. And on any job the Construction Act covers, taking the damages out of a payment means paying less than the notified sum, which requires a pay less notice, in time, stating the amount and basis (section 111). A deduction that skipped its conditions fails as a deduction this cycle, whoever caused the delay.

Check two: does the completion date they are counting from survive?

Damages run from the contractual completion date, as extended. Every week of extension of time you are entitled to moves the start line and erases that week of damages, which is why the extension is a shield first and a schedule second, and why delay from the client’s own side matters so much: unclaimed client delay is damages you are paying for their obstruction. If qualifying delay was never claimed, claim it now; late is worse than never only after the account closes.

Check three: is the rate what it claims to be?

A liquidated damages clause is enforceable when it protects a legitimate interest and is not extravagant or unconscionable against it; a rate that is really a threat rather than a genuine pre-estimate can be challenged as a penalty. Honest warning: this is the hardest of the three challenges and courts uphold agreed rates far more often than they strike them, so treat it as the last argument, not the first. The productive version of this check happens before signing: the rate in the particulars is a number you are agreeing to, so read it then, when it is still negotiable.

On a job for someone living in the house

A damages rate binds on a domestic job if the contract contains one, but two things change. The Act’s notice machinery does not apply to a residential occupier (section 106), so check one shrinks to whatever conditions the contract itself sets. And if the rate is in a consumer’s own favour in your standard terms, or an aggressive one in theirs, the consumer fairness test under the Consumer Rights Act 2015 is in play: a reasonable rate stands, a punitive one can be struck out entirely. Disputes end in the county court via a letter before action, not adjudication.

What to do this week

1. If a damages letter has arrived, run the three checks in order, in writing, before discussing the delay itself.

2. Sweep the job for unclaimed extensions and get the notices in: every awarded week is deleted damages.

3. On the next contract you sign, read the rate in the particulars and multiply it by a realistic overrun before agreeing it. That five minutes is the cheapest damages defence that exists.

Where the information stops

Whether a certificate was validly issued, how many weeks of extension your facts support, and whether a rate could be attacked as a penalty are the three questions these disputes are actually fought over, and when the deduction is serious, they deserve a professional hour before you take a written position, because your first letter frames all three.