WhatsApp messages – do you need to mark them “Subject to Contract”? 

If the recent case of Jaevee Homes v Fincham [2025] EWHC 942 (TCC) is anything to go by then it wouldn’t be a bad idea.   

In this latest case the Technology and Construction Court (TCC) reaffirmed that legally binding contracts can be formed via informal electronic platforms such as WhatsApp provided the language and context support it.

It also established that a construction contract can be valid even without agreement on key details like the project duration, start date, or payment terms as these terms can be implied by law.

Case summary

Fincham provided a quotation for demolition works which was followed by an exchange of WhatsApp messages. Jaevee then sent Fincham a formal sub-contract document along with its standard terms of business, but Fincham never responded.

A dispute later arose in relation to four unpaid invoices and Fincham commenced a smash and grab adjudication on the basis that the outstanding sums had become notified sums under the Scheme for Construction Contracts. In that adjudication Fincham successfully argued that the sub-contract document sent by Jaevee did not apply.

In Part 8 proceedings commenced by Jaevee, the TCC held that the exchange of WhatsApp messages evidenced and constituted a construction contract and that Jaevee's formal sub-contract document was sent too late and was not accepted by Fincham.

In reaching its decision the TCC decided what whilst the WhatsApp exchange did not include detail as to the duration, that fact, and even an absence of a start date or payment terms, were not essential terms which would prevent a construction contract being formed.

The decision in Jaevee has prompted us to consider what every contractor needs to know about contract formation.

What is a construction contract

A construction contract is a legally binding agreement between a contractor and the client (or employer), where a contractor agrees to carry out construction work in exchange for payment.

Key elements for contract formation

Taking things back to basics, ther e are essentially four legal elements that must be present for a contract to be formed:

1. Offer – a tender or quotation is usually considered an offer. It must clearly set out what you are agreeing to do including the price and scope of work.
2. Acceptance - the client must accept your offer without changes. If they respond with amendments or alternative terms, that is not acceptance.
3. Consideration - this simply means that both parties give something of value — you carry out the work, and the client pays for it. This must be clearly agreed.
4. Intention to create legal relations - in commercial work, this is assumed. If both parties act like there’s a contract, by starting work or making payments, the law will usually say there is intention to create legal relations.

Words of wisdom for contractors

• It’s common for contractors to be pressured to start work while paperwork is still being finalised. But starting work without a signed contract puts you at risk. Even if no contract is signed, a court can find that one exists based on conduct if you commence work and receive payment.

• If both parties are sending terms and conditions back and forth, be cautious. The contract may end up being concluded on terms not fully appreciated, especially if you start work without final confirmation.

• Ensure that you get everything in writing! Even a short email confirming the scope, price and payment terms is better than nothing!

• Review standard forms carefully. Just because it’s a standard contract, it doesn’t mean it’s fair. You should look for any amendments which may shift risk onto you.

• Make sure you understand the payment schedule, application process, and deadlines for notices.

Final thoughts

As a contractor, you face pressure to get started and keep clients happy but protecting your business starts with getting the contract right. A clear, properly formed construction contract ensures you know what you're delivering, how you’ll be paid, and how to deal with changes or disputes. Taking the time to lock in the details before starting work can save you time, money, and stress later.

Our specialist construction legal disputes and dispute avoidance legal team are well placed to provide advice in relation to construction contracts. For more information please contact Lee Ward or Chloe Wood.