Key Takeaways
- Exchange of contracts is the point at which the sale becomes legally binding — neither party can withdraw without significant financial penalties.
- At exchange, the buyer pays a deposit of usually 10% of the purchase price to their solicitor.
- The completion date is agreed at exchange — this is the day you move in.
- Buildings insurance must be in place from the moment of exchange.
- The typical gap between exchange and completion is 1–4 weeks.
What Does "Exchange of Contracts" Mean?
Exchange of contracts is the pivotal moment in any UK property transaction. Up until this point, either the buyer or seller can pull out of the deal without legal penalty (though there may be financial costs for work done). After exchange, the transaction is legally binding on both parties.
The exchange takes place between the two solicitors, who simultaneously swap the signed contracts by telephone — a process governed by the Law Society's Formula B (the most common method). Both parties have already signed identical contracts; the "exchange" refers to each solicitor holding the other party's signed copy.
When Does Exchange of Contracts Happen?
Exchange typically occurs after all of the following have been completed:
- Your mortgage offer has been formally issued in writing
- Your solicitor has completed all searches (local authority, environmental, drainage/water)
- The seller has answered all enquiries to your solicitor's satisfaction
- You have reviewed and approved the draft contract
- A completion date has been agreed by all parties in the chain
- Your surveyor's report has been received and any issues negotiated
In a typical transaction, exchange happens around 8–16 weeks after an offer is accepted, though this varies considerably depending on chain complexity, leasehold properties, and how responsive all parties are.
Step-by-Step: What Happens on Exchange Day
1. Solicitors confirm everything is in order
Both solicitors confirm they hold signed contracts, the deposit is ready, and all queries have been resolved.
2. You sign your contract
You'll have already signed your copy of the contract during the pre-exchange period. Your solicitor holds it ready.
3. The deposit transfers
You transfer the exchange deposit (usually 10% of the purchase price) to your solicitor. They hold it in their client account.
4. Solicitors "exchange" by phone
Both solicitors phone each other at a pre-agreed time. The seller's solicitor reads out the contract; the buyer's solicitor confirms their contract matches. Both confirm exchange. The date and time is logged.
5. Contracts are posted
Each solicitor posts the signed contract they hold to the other. This is a formality — exchange has already legally occurred at the point of the phone call.
6. You take out buildings insurance immediately
You are now legally responsible for the property (in England and Wales). Buildings insurance must be in place from this moment.
7. You book your removal company (if not already done)
Now you have a confirmed completion date, confirm your removal booking. If you haven't booked yet, do so immediately — popular slots fill fast.
The Exchange Deposit: How Much and Where Does It Go?
At exchange, the buyer pays a deposit — typically 10% of the purchase price — to their own solicitor, who holds it in their client account. This deposit is held until completion, when it is released as part of the final payment to the seller.
What Does the Contract Contain?
The sale contract — officially a "contract for the sale and purchase of land" — is a standard Law Society document containing:
- Full names and addresses of buyer and seller
- Property address and title number
- Purchase price and deposit amount
- Completion date
- What is included in the sale (fixtures and fittings list)
- Any special conditions agreed between the parties
- Indemnity clauses for any known issues (e.g., missing building regulations consent)
Exchange and Completion: What's the Difference?
| Feature | Exchange of Contracts | Completion |
|---|---|---|
| When it happens | Usually 1–4 weeks before completion | The agreed moving day |
| What becomes binding | Both parties legally committed to the sale | Ownership transfers |
| Money involved | 10% deposit paid | Remaining 90% paid via solicitor |
| Keys | No — you don't get keys yet | Yes — you get keys and can move in |
| Insurance | Buildings insurance required from this point | Update policy with new address |
| Can you pull out? | Yes (before exchange only, without penalty) | No — legally bound since exchange |
Simultaneous Exchange and Completion
"Sim ex and comp" — simultaneous exchange and completion — happens when both events occur on the same day. This is less common but can happen when:
- A chain has collapsed and all parties need a quick solution
- A cash buyer needs no mortgage funds release period
- A new-build property completes on a fixed developer date
The risk of simultaneous exchange and completion is that if anything goes wrong with the funds transfer on the day, you could find yourself without keys but legally obligated to complete — a very stressful situation. Your solicitor will advise on the risks.
What Can Go Wrong at Exchange?
Exchange day can be tense, especially in a chain. Common issues include:
1. A party in the chain pulling out before exchange
Until exchange, any party in the chain can withdraw. Gazumping (seller accepting a higher offer) and gazundering (buyer reducing their offer at the last moment) are both legal before exchange. This is why many buyers push for exchange as quickly as possible.
2. Mortgage offer expiring
Mortgage offers are typically valid for 3–6 months. If the transaction drags on, your offer may lapse and you'll need to reapply — which can cause delays or change the terms.
3. Searches or enquiries outstanding
Exchange cannot happen while outstanding searches or enquiries remain unresolved. Delays in local authority searches (which can take 3–8 weeks in some areas) are a very common cause of delayed exchange.
4. Funds not cleared in time
The exchange deposit must clear in your solicitor's client account before exchange can take place. Ensure funds are transferred at least 24–48 hours in advance.
5. Disagreement on completion date
In a long chain, agreeing a completion date that suits everyone can be complex. This is often the last sticking point before exchange and can cause significant delays.
Between Exchange and Completion: Your Checklist
- ☐ Take out buildings insurance immediately (required from exchange)
- ☐ Confirm removal company booking for completion date
- ☐ Give notice to your current landlord (if renting)
- ☐ Notify employers, DVLA, HMRC, banks, and subscriptions of new address
- ☐ Arrange Royal Mail mail redirect
- ☐ Start planning your packing
- ☐ Contact utility providers to arrange transfer on completion date
- ☐ Ensure mortgage funds are released to your solicitor before completion
- ☐ Arrange a meter reading at your old and new properties on moving day
- ☐ Confirm completion time with your solicitor (usually 12–2pm for funds to clear)
Scotland: A Different System
It's important to note that Scotland has a fundamentally different conveyancing system. In Scotland, there is no "exchange of contracts" as such. Instead, solicitors exchange "missives" — formal letters that constitute the binding contract. Once missives are "concluded" (all terms agreed and final letters exchanged), the sale is legally binding. This stage is roughly equivalent to exchange in England and Wales.
Another key difference: in Scotland, an offer accepted by the seller is not binding until missives are concluded. Gazumping is technically possible but culturally very rare in Scotland.
For more on the Scottish system, read our Scottish Conveyancing Guide.
Frequently Asked Questions
What happens on the day of exchange of contracts?
How long between exchange and completion?
Can the seller pull out after exchange of contracts?
Do I pay stamp duty at exchange or completion?
What if my mortgage offer expires before exchange?
Can I exchange and complete on the same day?
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