When you’re buying or selling a home in the UK, two key milestones in the process are exchange of contracts and completion. These terms are often used together, but they mean very different things and understanding the legal difference is essential to avoid confusion or costly mistakes.

In this blog, we’ll explain exactly what happens at each stage, why they matter, and what you should expect as a buyer or seller.

What Is Exchange of Contracts?

Exchange of contracts is the point in a property transaction when the buyer and seller legally commit to the sale/purchase.

Your solicitor or conveyancer will exchange signed contracts with the solicitor acting on behalf of the other party (either buyer or seller). Once the contracts are exchanged:

• Both parties are legally bound to go through with the transaction.

• The completion date is set (this can be the same day or a future date).

• The buyer usually pays a deposit, typically 10% of the purchase price.

• If either party pulls out after exchange, they could face financial penalties or legal action.

Key point to note: After exchange, the transaction is legally binding. Up until this point, either party can withdraw without legal or financial consequences.

What Is Completion?

Completion is the day the sale is officially finalised, and ownership of the property is transferred from the seller to the buyer.

On completion day:

• The buyer’s solicitor sends the remaining balance of the purchase price to the seller’s solicitor.

• The keys are handed over to the buyer (usually via the estate agent).

• The buyer can move into the property.

• The title deeds and documents are updated at the Land Registry.

Key point to note: Completion is when the buyer becomes the new legal owner and can take possession of the property.

How Long Between Exchange and Completion?

This varies, but it’s typically between 7 to 14 days. In some cases, both can happen on the same day — this is known as a simultaneous exchange and completion, often used for chain-free sales or urgent moves.

Time between exchange and completion may also depend on your lenders requirements too as they will have certain stipulations for required notice in order to release funds to your Solicitor.

What Happens If Something Goes Wrong?

If the buyer pulls out after exchange: They may lose their deposit and be liable for damages.

If the seller pulls out: They may face legal action from the buyer and have to pay compensation.

Delays to completion can happen due to late mortgage funds, admin errors, or issues higher up in a chain — your Solicitor will help manage this.

Final Thoughts

The difference between exchange of contracts and completion is simple but significant:

• Exchange is the legal commitment.

• Completion is the handover of ownership.

Understanding the legal process helps you plan with confidence, avoid stress, and know your rights and responsibilities at every stage.

Need Legal Help with Buying or Selling?

Whether you’re a first-time buyer or a seasoned seller, our expert conveyancing team are here to guide you through every step — from initial instruction to final completion.

Get in touch today for friendly, jargon-free legal advice on your next property move.

You can also complete an online enquiry form. One of the Wollens team will contact you as soon as they are available.