Buying or selling property in England and Wales involves a key document: the contract for sale (also called the sale and purchase agreement). A crucial question for buyers and sellers is when they actually become legally committed. In a typical private-treaty transaction, the answer is exchange of contracts. Other structures differ: at auction, for example, a binding contract is usually formed at the fall of the hammer. Understanding when you are bound avoids costly mistakes. Here is a plain-English guide.
What is the contract for sale?
The contract for sale is the agreement that sets out the terms on which the property is sold, the parties, the property, the price, the deposit, the completion date, and what is included. In a typical residential transaction it incorporates the Standard Conditions of Sale (or, for commercial property, the Standard Commercial Property Conditions), which supply detailed standard terms.
The formality: it must be in writing (section 2)
A contract for the sale (or other disposition) of an interest in land is subject to strict formalities under section 2 of the Law of Property (Miscellaneous Provisions) Act 1989. It must:
- be in writing;
- incorporate all the expressly agreed terms (in one document or, where contracts are exchanged, in each); and
- be signed by or on behalf of both parties.
If these formalities are not met, there is generally no binding contract, which is why an informal "agreement" or a handshake to buy a house is not legally enforceable.
"Subject to contract", you are NOT yet bound
When a sale is agreed (usually through estate agents), it is almost always marked "subject to contract". This is vital: it means neither party is legally committed yet. Up to the moment of exchange, either side can pull out (the source of "gazumping" and "gazundering"), generally without legal liability for the sale itself. Solicitors carry out searches, enquiries and checks during this pre-contract stage.
Exchange of contracts, the binding moment
The transaction becomes legally binding at exchange of contracts: the parties' signed contracts are formally exchanged (often by the solicitors), and the buyer usually pays a deposit (commonly 10%). From exchange:
- both parties are committed, the seller must sell and the buyer must buy;
- a completion date is fixed; and
- pulling out after exchange is a serious breach, the defaulting party can lose the deposit (buyer) and face a claim for damages, and possibly specific performance.
Completion, the final step
On the agreed completion date, the balance of the price is paid and the buyer takes possession; the buyer ordinarily acquires the beneficial interest in the property. For registered land, however, legal title is not transferred until registration at HM Land Registry; completion alone does not vest the legal estate. The buyer's solicitor deals with SDLT and registration promptly after completion.
So, will I be bound?
- Before exchange (subject to contract): generally no, you can withdraw.
- At and after exchange: yes, you are legally bound, and withdrawing has serious financial consequences.
Key takeaways
- The contract for sale sets out the terms; it must meet the section 2 (LP(MP)A 1989) formalities, in writing, all terms included, signed by both.
- While the deal is "subject to contract", neither party is bound and either can walk away.
- You become legally committed at exchange of contracts (when a deposit is usually paid); pulling out then can mean losing the deposit and facing damages or specific performance.
- Completion transfers the beneficial interest; for registered land, legal title passes only on Land Registry registration, followed by SDLT payment.
Sources
- Law of Property (Miscellaneous Provisions) Act 1989, s 2 (formalities for contracts for the sale of land)
- Standard Conditions of Sale / Standard Commercial Property Conditions; conveyancing practice on exchange and completion
- SDLT (Finance Act 2003) and HM Land Registry registration on completion
--- This article is general information about the law of England & Wales as at 2026, not legal advice. For advice on your circumstances, consult a qualified solicitor or conveyancer.