United Kingdom Edition
Definition

What is Exchange of Contracts?

A complete guide to exchange of contracts - the moment a property sale becomes legally binding, what happens, and what it means for buyers and sellers.

Exchange of Contracts Definition

Exchange of contracts is the pivotal moment in a property transaction in England and Wales when the sale becomes legally binding. Before exchange, either party can withdraw without penalty - after exchange, pulling out carries severe financial consequences.

At exchange, both buyer and seller have signed identical contracts. The buyer's solicitor and the seller's solicitor then swap (exchange) these contracts, usually over the telephone using the Law Society's Formula B or C. The buyer pays a deposit, and a completion date is fixed.

What Happens Before Exchange

Before exchange can take place, several things must be in order:

  • Searches: Local authority searches, environmental searches, water and drainage searches
  • Survey: The buyer's survey and/or valuation must be completed
  • Mortgage offer: The buyer's formal mortgage offer must be in place
  • Title investigation: The buyer's solicitor must be satisfied with the title
  • Enquiries: All pre-contract enquiries must be answered to the buyer's solicitor's satisfaction
  • Deposit: The buyer must have the exchange deposit funds available
  • Buildings insurance: The buyer should have buildings insurance ready to start from exchange (risk passes to the buyer at exchange)
  • Chain readiness: If part of a chain, all parties in the chain must be ready to exchange simultaneously

What Happens at Exchange

  • Both solicitors confirm the contract terms are agreed
  • The buyer's solicitor sends the signed contract and deposit to the seller's solicitor
  • The seller's solicitor releases the seller's signed contract to the buyer's solicitor
  • A completion date is formally agreed and recorded in the contract
  • The deposit (typically 10% of the purchase price) is transferred
  • Both parties are now legally bound to complete on the agreed date
  • The buyer should arrange buildings insurance from this moment

The Deposit at Exchange

The standard exchange deposit is 10% of the purchase price. For a £400,000 property, this means £40,000. The deposit is held by the seller's solicitor (or, in a chain, passed up the chain to fund each seller's onward purchase).

It is sometimes possible to negotiate a reduced exchange deposit (e.g. 5%), particularly if the buyer's mortgage deposit is less than 10%. This must be agreed between the parties before exchange. A 10% deposit provides stronger protection for the seller because it is forfeited if the buyer defaults.

After Exchange: The Path to Completion

Between exchange and completion:

  • The buyer's solicitor requests the mortgage funds from the lender
  • The buyer arranges the remaining balance (completion funds minus the exchange deposit)
  • Final checks are carried out (e.g. bankruptcy search on the buyer, priority search at the Land Registry)
  • The buyer prepares for moving day
  • The seller prepares to vacate the property

What If You Need to Pull Out After Exchange?

Withdrawing after exchange is possible but extremely costly:

  • Buyer pulls out: Forfeits the exchange deposit (e.g. £40,000 on a £400,000 property). The seller can also sue for damages - the difference if the property sells for less, plus costs
  • Seller pulls out: Must return the deposit and may be sued by the buyer for breach of contract, including the buyer's wasted costs and any price difference
  • In a chain: One party withdrawing can cause a chain collapse, with claims passing through each linked transaction

Frequently Asked Questions

Exchange of contracts is the point in a property purchase when both buyer and seller become legally committed to the transaction. Both parties sign identical contracts, which are then swapped (exchanged) by their solicitors, usually by telephone. After exchange, neither party can withdraw without significant financial consequences.

PT

PropertyWiki Team

Editorial Team

Published: April 7, 2026

Updated: April 7, 2026

The PropertyWiki editorial team brings together property experts, solicitors and market analysts to provide clear, accurate guidance on UK real estate.