Exchange of Contracts and Completion Day

Exchange of contracts is the point in a property transaction when the sale becomes legally binding on both parties. Before exchange, either the buyer or seller can walk away without financial penalty. After exchange, both sides are contractually committed to completing the purchase at the agreed price and on the agreed date.

During the earlier stages of buying a home, you will have had your offer accepted, instructed a solicitor, arranged a mortgage, and completed property searches. Throughout that entire period, nothing is legally binding. Your solicitor will have been working through the conveyancing process, raising enquiries, reviewing the title, and negotiating the contract terms. But until contracts are exchanged, the agreement exists only as an intention rather than a legal obligation.

Exchange of contracts changes that. Once your solicitor and the seller's solicitor formally swap signed copies of the contract over a recorded telephone call, both sides are locked in. The completion date is fixed, the deposit is transferred, and pulling out carries serious financial consequences including forfeiting your deposit and potential legal action for breach of contract.

The contract exchanged between the parties contains the agreed purchase price, the completion date, details of what is included in the sale such as fixtures and fittings, and any special conditions. Both the buyer and seller sign identical copies of the contract before exchange takes place. In England and Wales, exchange typically happens 8 to 12 weeks after your offer is accepted, though the timeline varies depending on the complexity of the chain, how quickly conveyancing searches come back, and whether any issues arise.

The exchange of contracts follows a specific sequence handled by your solicitor. Understanding each step helps you know what to expect and what you need to do before exchange day.

Before exchange can happen, your solicitor confirms that all pre-exchange requirements are met. Your mortgage offer must be formally issued and still within its validity period, all search results must be received and reviewed, all enquiries raised must be resolved, and both parties must have agreed the contract terms including the completion date. You sign the contract and send it to your solicitor alongside your deposit funds.

The actual exchange happens through a recorded telephone call between the two solicitors. During this call, they read out key details of the signed contracts to confirm they match, formally agree the completion date, and confirm that contracts are now exchanged. The Law Society's Formula B is most commonly used, which sets out the standard undertakings each solicitor gives to the other during the call.

After the call, your solicitor transfers the deposit electronically to the seller's solicitor. The original signed contracts are then posted to each other, so each side holds the contract signed by the other party. Your solicitor confirms the exchange to you, typically by phone or email on the same day. From this moment, you are legally committed to completing the purchase on the agreed date.

At exchange of contracts, you pay a deposit to the seller's solicitor. The standard exchange of contracts deposit is 10% of the purchase price, though in practice many buyers pay a reduced deposit of 5% with agreement from both solicitors.

The deposit amount is negotiated between the solicitors during the contract drafting stage. If you are buying with a 95% mortgage, you may only have 5% available, and your solicitor will negotiate this with the other side. Most sellers accept a 5% deposit without issue. On a property priced at £300,000, a 5% deposit means transferring £15,000 to your solicitor's client account before exchange, while a 10% deposit requires £30,000.

Your deposit funds must be cleared in your solicitor's client account before exchange can proceed. Bank transfers can take up to 24 hours to clear, so send your deposit at least two working days before the planned exchange date. Your solicitor will confirm when the funds have arrived and cleared.

If you are selling a property at the same time as buying, your solicitor can sometimes use the deposit received from your buyer towards the deposit on your onward purchase. This is known as using the deposit up the chain and reduces the cash you need to have available. However, this only works if your sale exchanges simultaneously with or before your purchase.

Many buyers confuse exchange of contracts with completion, but they are two distinct stages in the property purchase process. Understanding the difference between exchange and completion helps you plan your timeline and finances correctly.

Exchange of contracts is when the sale becomes legally binding. You pay your deposit, the completion date is fixed, and both parties are committed to the transaction. However, you do not own the property at this point. The seller still holds the legal title, you cannot move in, and you cannot make any changes to the property. What you gain at exchange is the certainty that the sale will proceed, plus the legal right to enforce it if the other party tries to back out.

Completion is when the remaining purchase funds are transferred, ownership passes to you, and you collect the keys. On completion day, your solicitor sends the balance of the purchase price to the seller's solicitor. Once receipt is confirmed, the estate agent releases the keys and you can move into your new home. Your solicitor then registers the transfer of ownership with HM Land Registry and pays any stamp duty due on your behalf.

The gap between exchange and completion gives both parties time to prepare for moving day. Sellers arrange their removal, buyers finalise logistics, and solicitors prepare the completion statements and transfer documents.

The time between exchange of contracts and completion typically ranges from 7 to 28 days, with two weeks being the most common gap. The completion date is agreed between the buyer and seller during contract negotiations and becomes fixed at the point of exchange.

Several factors influence how long this period lasts. If you are in a property chain, the completion date needs to work for every buyer and seller in that chain, which often requires a longer gap for coordination. First-time buyers purchasing a chain-free property may agree a shorter gap of just 7 days. Complex chains with multiple transactions may require up to 28 days to align everyone's timelines.

Same-day exchange and completion is possible and happens regularly in straightforward, chain-free transactions. Your solicitor handles the exchange by telephone in the morning, and the purchase funds are transferred immediately afterwards. However, this approach carries more risk. If funds are delayed or a last-minute issue arises, there is no buffer time to resolve it before you are expected to move in.

The table below shows a worked example timeline for a standard two-week gap between exchange and completion. For a full breakdown of the journey from offer to keys, see the guide on how long conveyancing takes.

Once contracts are exchanged, pulling out of the transaction has serious financial and legal consequences. This applies equally to buyers and sellers, though the remedies available to each side differ.

If the buyer pulls out after exchange of contracts, they forfeit their entire deposit. On a £300,000 property with a 10% deposit, that means losing £30,000. The seller can also sue for any additional losses, such as the difference if they later sell at a lower price, costs of remarketing the property, and expenses from their own onward purchase falling through.

If the seller pulls out after exchange, the buyer can take legal action for breach of contract. The buyer's deposit must be returned in full, and the seller may be liable for the buyer's conveyancing fees, survey costs, mortgage arrangement charges, and the cost of alternative accommodation. The buyer can also apply to the court for an order of specific performance, which compels the seller to complete the sale as originally agreed.

A common concern is gazumping, where a seller accepts a higher offer from another buyer after yours has been accepted. This can only happen before exchange of contracts. If you are worried about being gazumped, understanding gazumping and gazundering can help you take steps to protect yourself during the pre-exchange period. Once contracts are exchanged, the seller is legally bound to sell to you at the agreed price.

If either party fails to complete on the agreed date, the other side's solicitor can serve a Notice to Complete. This gives the defaulting party 10 working days to complete the transaction. If they still fail to do so, the innocent party can rescind the contract and claim damages.

Completion day is when you officially become the legal owner of your new property and collect the keys. Knowing what happens and preparing in advance helps the day run smoothly.

On the morning of completion, your solicitor transfers the remaining purchase funds to the seller's solicitor. If you have a mortgage, your lender sends the mortgage advance to your solicitor, who combines it with any remaining balance you owe and sends the total to the seller's solicitor. This transfer usually happens between 9am and 11am, but confirmation of receipt can take until early afternoon depending on the banking system and the number of transactions in the chain.

Once the seller's solicitor confirms receipt of the funds, they notify the estate agent, who releases the keys to you. Most buyers collect keys from the estate agent's office between midday and 3pm. If you are at the end of a long chain, it could be later in the afternoon, so avoid scheduling your removal van for first thing in the morning.

Your solicitor handles all post-completion work. This includes paying stamp duty to HMRC within 14 days of completion, submitting the application to register your ownership with HM Land Registry, and sending you a detailed completion statement showing all costs and disbursements. Registration with HM Land Registry can take several weeks, but your ownership is legally effective from the date of completion.

To prepare for completion day, confirm your removal company booking well in advance, arrange utility transfers and meter readings for the day, notify your local authority about council tax, and keep your phone nearby so your solicitor can reach you with updates throughout the day.