Work has started and the contract is not signed. What applies?

First, the reassurance: working without a signature is not working without a contract. A contract forms by conduct, you quoted, they said go ahead or simply let you start, work began, money changed hands. The law reads that as agreement. Signature is evidence of a contract, not an ingredient of one, the email page covers the formation mechanics.

So which terms apply? The ones that actually got agreed

The contract-by-conduct contains whatever was communicated and accepted before or while work proceeded: the quote’s scope and price if the quote was the basis, the stages discussed in the thread, the start date everyone acted on. What it does not contain is everything else. No agreed damages rate means no liquidated damages. No agreed retention means no right to hold one. No extension machinery means client delay lands in the crude world of time at large. The unsigned job is not lawless; it is sparse, and sparse hurts whichever side needed the missing term.

Watch for the draft that never got signed: if a form was sent, negotiated and then everyone behaved as if it governed, its terms may have been incorporated by conduct anyway, in which case you are bound by a document you never signed. That cuts both ways too, and it is one of the first things an adviser will ask about.

Three floors that exist even when nothing was written

• The Construction Act does not care about signatures. Since the law changed in 2011 it applies to construction contracts whether written or oral, so on a business job the payment machinery runs: where no adequate payment terms were agreed, the Scheme supplies them, due dates, notice windows, final dates, and on jobs over 45 days the right to stage payments (section 109, covered here). An unsigned business job has more statutory protection than most builders assume.
• Work done must be paid for. Even where no contract can be pieced together at all, rare, but it happens when parties never got past “we will sort the details”, the law of unjust enrichment gives a claim for a reasonable sum (quantum meruit) for work the client requested and received. Slower and vaguer than a contract price, but a floor, not a void.
• Consumer law still applies on a domestic job: work done for a consumer must be done with reasonable care and skill and, where no price was fixed, at a reasonable price, and with a residential occupier the Act is off anyway (section 106), so the sparse contract is the whole game, which is why the fix below matters most there.

The fix is a consolidating letter, not a time machine

You cannot back-date a signature, and pushing a fresh onerous form at a client mid-job reads badly and may not bind. What works is the consolidating email from the email page, scaled up: one message setting out scope, price, stages, dates and the variations procedure as you both understand them today, ending “reply to confirm and this is what we are working to”. Their yes turns the sparse contract into a documented one from here forward. Most clients reply within the hour, because the letter also protects them, and a client who refuses to confirm any terms at all has told you something worth knowing in week three rather than week thirty.

What to do this week

1. Reconstruct what was actually agreed: the quote, the thread, the payments made. That pile is your contract; read it as a stranger would.

2. Send the consolidating letter, and get the reply.

3. Change the habit that got you here: no start before the quote is accepted in writing, with the nine things in it. The whole page you have just read is the cost of skipping that.

Where the information stops

Which terms made it into a contract by conduct is decided on the whole course of dealing, and it is genuinely hard to call from inside; if the job is already in dispute, resist the urge to send any consolidating letter before advice, because on a contested file that letter is evidence too, and it should be drafted as such.