Are WhatsApp agreements legally binding in the UK?

The medium matters less than the content

In England and Wales, most business contracts do not have to be in a particular form. They can be made in writing, verbally, or through conduct. A contract made through WhatsApp messages is assessed in the same way as one made in an email exchange or a conversation: by asking whether the usual elements of a contract are present.

So the useful question is not "is WhatsApp legal?" but "did these messages show that both sides agreed clear terms and meant to be bound by them?"

What a court would generally look for

The general elements of a contract are an offer, an acceptance of that offer, something of value given by each side (known as consideration — usually payment in return for goods or services), an intention to create legal relations, and terms that are certain enough to be enforced. Our guide to what makes a contract legally binding explains each of these.

In a chat, problems usually arise with acceptance and certainty. A reply such as "sounds good" might be acceptance, or it might be agreement in principle with details still to follow. A thumbs-up emoji is open to interpretation. And if key terms like price or scope were never settled, there may be nothing definite enough to enforce.

Where two businesses are dealing with each other, it is generally presumed that they intend their agreement to be legally binding, unless the messages show otherwise.

"Subject to contract" and agreements to agree

If someone writes that a deal is "subject to contract", that is usually a sign that they do not intend to be bound until a formal written contract is signed. Similarly, a message agreeing to "sort out the details later" may show that a binding agreement has not yet been reached, because essential terms are still open.

These are not absolute rules — courts look at the whole exchange and the parties' conduct — but they are good reasons to be cautious about relying on an informal chat alone.

Agreements that need more than a chat

Some kinds of agreement have special formality rules. For example, contracts for the sale or other disposition of an interest in land must be in writing, include all the agreed terms, and be signed by or on behalf of each party; a guarantee generally needs to be evidenced in writing and signed by the guarantor; and a deed signed by an individual must be signed in the presence of a witness who attests it. Companies have their own execution rules. A WhatsApp exchange is unlikely to satisfy these requirements, so take advice if your deal falls into one of these categories.

Proving what was agreed

Even when a chat does form a contract, proving its terms can be difficult. Messages may be deleted, phones replaced, and chats may contain several versions of the same term. Screenshots can be disputed if the full thread is not available.

Practical steps that help include keeping a full export of the chat, summarising the final agreed terms in a single message and asking the other person to confirm, and turning the agreed terms into a written agreement that both sides sign.

How OfClause can help

OfClause lets you paste the relevant part of a WhatsApp chat and review each term it finds, with the status of the term and a link to its source message. Unclear acceptance is flagged rather than assumed, and the draft is built only from terms you confirm. The result is a written agreement record the other side can review and sign — a clearer basis than a scroll of messages. It does not decide whether your chat is legally binding.

A practical checklist for chat deals

Before you treat a WhatsApp exchange as your agreement, it is worth asking a few questions. Is it clear who the parties are, including the full business names? Is the price stated, and is it clear whether VAT is included? Is the scope of the work or the goods described specifically enough that a stranger could tell what was promised? Did the other side clearly accept the final version of the terms, rather than an earlier one? Are there dates for delivery and payment?

If the answer to any of these is no, the chat may still be useful evidence, but it leaves room for argument. Sending one message that sets out the final terms and asking for a clear "yes, agreed" reply is a simple improvement. A short written agreement signed by both sides is better still.

Group chats deserve extra care. When several people are in a chat, make sure the person agreeing has authority to commit their business, and that the terms you are relying on were addressed to the right party.