We Agreed a Fix: Then They Changed Their Mind

‍‌‌​‌​​‌​‌‌​‌‌‌​​‌​‌​‌‌‌‌‌​‌​‍You've had the big row, hammered out a resolution, maybe even shook hands or swapped emails -- then the client changes their mind. Classic. The law will sometimes hold them to it and sometimes say "that was just negotiation". The trick is knowing the difference and setting things up so your deals actually stick.

There are three big ideas here: binding settlement contracts, estoppel (promises you relied on), and the without prejudice / subject to contract labels.

1. When is a "deal" actually a binding settlement?

Nothing magic -- a settlement is just a contract about how to end or adjust your dispute. Same basics: offer, acceptance, intention to create legal relations, and clear enough terms.

A settlement is more likely to be binding if:

• The offer is clear: "We will pay you £X in full and final settlement of [dispute], payable by [date]."

• You clearly accept: "We accept your offer of £X in full and final settlement of this dispute."

• There's no "subject to contract" caveat -- that wording usually means "not binding until formal document is signed".

• The essentials are all there: parties, amount, what claims are covered, timing, any conditions (e.g. payment date, works to be done).

Courts have enforced settlement deals reached just in letters/emails where the wording showed a complete bargain, even without a later formal document.

If you've got that, you don't argue estoppel; you argue "binding settlement contract -- now enforce it".

2. When "without prejudice" and "subject to contract" kill your argument

These two labels matter a lot.

• "Without prejudice" usually means the communication is protected from being shown to the court as an admission or offer if settlement fails -- it's there to let people talk frankly.

• "Subject to contract" is a big red flag: it signals that nothing is binding until a formal contract is signed.

So if your "agreement" sits in an email labelled "without prejudice and subject to contract", and the formal document is never signed, a court may well say: this was only negotiation, no final contract, even if you wrote "agreed in principle".

There are exceptions (e.g. clear waiver of WP, or conduct showing both sides treated it as final), but don't bank on them. Better to get what matters set out outside those labels once you've got a deal.

3. Where estoppel can help (and where it can't)

If you don't have a clean settlement contract, you sometimes fall back on promissory estoppel -- the idea that it can be unjust to let someone go back on a clear promise you relied on.

Very simplified, you're looking for:

• A clear promise or representation that they won't insist on their strict rights or will do something specific (e.g. "we will accept £X as full and final"; "we won't deduct LDs if you finish by [date]").

• Reliance -- you changed your position because of that promise (e.g. carried on working, didn't adjudicate, didn't sue, turned down other work).

• Unconscionability -- it would be plainly unfair to let them go back on it in all the circumstances.

If you can show those, a court can stop them from enforcing their strict rights in that area, or hold them to the concession for a period.

But:

• Estoppel is a shield more than a sword -- it's often used to defend against something (like LDs), not to create a whole new standalone claim.

• It won't rewrite a properly drafted contract just because the outcome feels harsh. Courts use it sparingly.

So your Plan A should always be "get a clear written settlement", not "hope estoppel will save me later".

4. Practical playbook when a client backtracks

Step 1 -- Work out what you actually have

• Do you have emails/letters with a clear offer and clear acceptance, without "subject to contract"? If yes, you may have a binding settlement.

• Is all of it under "without prejudice"? If so, you may be blocked from showing it in court unless both sides waive that privilege or you fall into an exception.

• Did you change your position based on a clear promise (carry on works, not adjudicate) in a way that would make it obviously unfair for them to renege? That's where estoppel might come in.

Step 2 -- Decide your leverage route

You've basically got three levers:

• Enforce the settlement -- treat it as a contract and push for payment/compliance (including adjudication if the settlement is a variation of the original construction contract and the adjudication clause still applies).

• Use estoppel as a defence -- if they try to hit you with LDs or revive claims they'd "parked", argue they're estopped from doing so because of their previous promise and your reliance.

• Re-open the original dispute -- if there's no binding deal, you're back into adjudication/mediation/court on the original issues, but now with a better sense of their bottom line.

Step 3 -- Tidy up, properly, next time

• When you think you've agreed terms in a mediation/meeting/phone call, follow up with a short non-WP email: "Further to today's discussions, this confirms the settlement we agreed..."

• Get a simple written settlement agreement signed, even if it's only a couple of pages, covering: who pays what, when; what claims are waived; what happens if someone doesn't do what they promised.

• Be careful with "without prejudice" and "subject to contract" labels -- use them while negotiating, but once the deal is final, you want a clean, binding version without those caveats.

That's how you go from "we shook on it and they bottled it" to "here's the signed deal we're now enforcing".

Disclaimer: SiteKiln gives you plain-English information, not legal advice. Talk to a solicitor before making big decisions on live disputes.

What to do next

• Go through your emails and messages right now and work out whether you have a clear offer, clear acceptance, and no "subject to contract" caveat -- that is the core test for a binding settlement.
• If you think there is a binding deal, write to the other side confirming the terms and asking them to comply.
• If negotiations are still going, follow up any verbal agreement with a short non-"without prejudice" email confirming what was agreed.
• Get a simple written settlement agreement signed, even if it is only a couple of pages, covering who pays what and when, what claims are waived, and what happens if someone does not deliver.
• If the other side has gone back on a deal and you have changed your position in reliance on their promise, take advice on estoppel and enforcement options.

Sources

• Housing Grants, Construction and Regeneration Act 1996 -- https://www.legislation.gov.uk/ukpga/1996/53/contents
• Civil Procedure Rules -- https://www.justice.gov.uk/courts/procedure-rules/civil

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