Mortgage Deposit vs Exchange Deposit Explained

The word deposit is used several times when buying a house, but it does not always mean the same thing. Two of the most important terms are the mortgage deposit and the exchange deposit.

Your mortgage deposit affects how much you borrow from the lender. Your exchange deposit is a contractual payment made when you become legally committed to buying the property.

Simple answer: The mortgage deposit is your total contribution towards the purchase price. The exchange deposit is the amount transferred through your conveyancer when contracts are exchanged. The same savings may fund both, but the amounts and payment dates can be different.

Understanding the difference helps buyers calculate how much money must be available before exchange and how much will still be needed for completion.

Mortgage Deposit and Exchange Deposit at a Glance

Question	Mortgage Deposit	Exchange Deposit
What is it?	Your total cash contribution towards the property price	A contractual deposit paid when contracts are exchanged
Who requires it?	The mortgage structure and lender’s loan-to-value requirements	The property purchase contract and seller
When is it paid?	Used as part of the purchase funds by completion	Normally immediately before or at exchange
How much is it?	Often 5%, 10%, 15%, 20% or more	Traditionally 10%, although a smaller amount may be agreed
Who receives it?	Usually transferred through the buyer’s conveyancer as part of the purchase money	Transferred through the buyer’s and seller’s conveyancers
What does it affect?	Mortgage amount, LTV and available mortgage products	Your contractual commitment to complete the purchase

What Is a Mortgage Deposit?

A mortgage deposit is the part of the property price that you fund without using the main mortgage loan.

For example, if you buy a home for £300,000 using a £270,000 mortgage:

Property price: £300,000
Mortgage: £270,000
Mortgage deposit: £30,000
Deposit percentage: 10%
Loan-to-value: 90%

The deposit does not normally get paid directly to the mortgage lender. Your conveyancer combines your money with the mortgage funds and transfers the purchase money as part of legal completion.

Mortgage Deposit Formula

Property price − mortgage amount = mortgage deposit

You can also calculate it using a percentage:

Property price × deposit percentage = mortgage deposit

Why Does the Mortgage Deposit Matter?

The deposit determines the loan-to-value ratio, commonly called LTV. LTV shows how much of the property’s value is being funded by the mortgage.

A larger deposit creates a lower LTV. This may provide access to a wider selection of mortgage products or different interest rates, subject to the lender’s affordability and eligibility checks.

What Is an Exchange Deposit?

The exchange deposit is paid when contracts are exchanged. In England and Wales, exchange of contracts is normally the stage when the buyer and seller become legally committed to the transaction.

The exchange deposit is traditionally 10% of the purchase price, although a different amount can sometimes be agreed between the buyer and seller.

Your conveyancer will normally:

tell you how much must be available for exchange;
provide verified client-account payment details;
check that the funds have cleared;
agree the deposit arrangement with the seller’s conveyancer; and
transfer or legally account for the deposit when contracts are exchanged.

The exchange deposit becomes part of the total purchase price. It is not an extra payment added on top of the property’s agreed price.

Important: Do not transfer a large deposit using bank details received only by email. Property transactions are targeted by payment-redirection fraud. Confirm the conveyancer’s bank details using a trusted telephone number before sending money.

Are the Mortgage Deposit and Exchange Deposit the Same Money?

Often, yes. The buyer’s savings can be used to pay the exchange deposit first, with the remaining savings and mortgage funds being used at completion.

However, the amounts may be different.

Example: Both Deposits Are 10%

You buy a property for £300,000 with a 90% mortgage:

Mortgage amount	£270,000
Total mortgage deposit	£30,000
10% exchange deposit	£30,000
Remaining purchase money at completion	Normally provided by the mortgage lender, plus any separate fees or adjustments

In this example, the mortgage deposit and exchange deposit are the same amount.

Example: Mortgage Deposit Is Larger Than 10%

You buy a property for £300,000 with an 80% mortgage:

Mortgage amount	£240,000
Total mortgage deposit	£60,000
10% exchange deposit	£30,000
Remaining buyer contribution at completion	£30,000

Here, half of the buyer’s total deposit is paid at exchange and the remaining contribution is paid before completion.

What If You Have a 5% Mortgage Deposit?

A buyer using a 95% mortgage may have only a 5% cash contribution. However, the draft purchase contract may still refer to a traditional 10% exchange deposit.

For a £300,000 property:

5% mortgage deposit: £15,000
Traditional 10% exchange deposit: £30,000
Potential shortfall at exchange: £15,000

This does not necessarily prevent the purchase. The buyer’s conveyancer may ask the seller to accept a reduced 5% deposit at exchange.

The seller does not automatically have to agree. The deposit amount must be discussed and agreed before contracts are exchanged.

Hidden risk: Paying only 5% at exchange may not always limit the buyer’s contractual liability to 5%. Under commonly used contract conditions, a buyer who fails to complete may be required to make the deposit up to 10%, depending on the contract.

Your conveyancer should explain the agreed deposit clause and the consequences before requesting your authority to exchange.

What Happens to the Deposit in a Property Chain?

A property chain may include several people selling and buying at the same time. The deposit paid by the buyer at the bottom of the chain is often passed up the chain and used towards each connected purchase.

Property Chain Example

Buyer A purchases a home from Seller B for £250,000 and pays a £25,000 deposit.
Seller B is buying another home for £400,000.
A full 10% deposit on Seller B’s purchase would be £40,000.
The £25,000 received from Buyer A may be passed up the chain.
Seller B may need to provide a £15,000 top-up, or the next seller may agree to accept the smaller deposit.

The Law Society explains that deposits passed through a chain can be less than 10% of the higher purchase prices. Conveyancers must agree how the deposit will be treated before exchange.

A buyer who is selling and buying should not assume that the deposit received on their sale will automatically cover the deposit needed for their purchase.

Where Must the Exchange Deposit Come From?

The buyer’s conveyancer and mortgage lender will normally need evidence showing where the money came from.

Common sources include:

personal savings;
proceeds from selling another property;
a gifted deposit from a family member;
a Lifetime ISA;
an inheritance;
investments that have been sold;
overseas savings; or
another source accepted by the lender and conveyancer.

Gifted Deposits

If another person provides part of the deposit, the lender and conveyancer will usually require information about:

the donor’s identity;
the donor’s relationship to the buyer;
the source of the donor’s funds;
whether the money is a genuine gift;
whether repayment is expected; and
whether the donor expects any legal interest in the property.

A deposit described as a gift when it is actually a loan could affect the mortgage application and affordability assessment.

Lifetime ISA Funds

Buyers using a Lifetime ISA should tell their conveyancer early. The conveyancer must follow the scheme process and allow enough time to request the funds.

Do not assume Lifetime ISA money will be immediately available for an unexpected exchange date.

When Should the Exchange Deposit Be Transferred?

Your conveyancer will provide a deadline based on the proposed exchange date. The money normally needs to be cleared in the conveyancer’s client account before exchange can take place.

Buyers should allow time for:

bank transfer limits;
security checks by the sending bank;
source-of-funds checks;
Lifetime ISA withdrawals;
investment withdrawals;
international money transfers; and
gifted-deposit documents.

A large transfer may need to be arranged in advance. Some banks have lower daily transfer limits for online or mobile banking.

Never send the deposit to the estate agent or seller unless your conveyancer has specifically explained and approved the arrangement.

What Happens to the Rest of the Money?

Before completion, the buyer’s conveyancer prepares a completion statement. This normally shows:

the agreed purchase price;
the exchange deposit already paid;
the mortgage funds expected from the lender;
the remaining buyer contribution;
Stamp Duty, LTT or LBTT;
legal fees and searches;
Land Registry fees;
leasehold or management-company charges;
bank transfer fees; and
any other agreed adjustments.

The buyer transfers the remaining balance to the conveyancer before completion. The lender then sends the mortgage advance, and the conveyancer transfers the completion money to the seller’s conveyancer.

What Happens to the Deposit If the Purchase Falls Through?

Before Exchange

In England and Wales, the buyer and seller are not normally legally committed until contracts are exchanged. If the purchase ends before exchange, no contractual exchange deposit should have been paid to the seller.

The buyer may still lose other expenses already paid, such as survey fees, searches, mortgage charges or legal costs.

After Exchange

Once contracts have been exchanged, the buyer is normally legally committed to complete on the agreed date.

If the buyer fails to complete, possible consequences may include:

loss of the exchange deposit;
a requirement to make a reduced deposit up to the contractual amount;
interest for completing late;
a notice to complete;
the seller ending the contract; and
a claim for additional losses suffered by the seller.

If the seller fails to complete, the buyer may be entitled to recover the deposit and pursue other contractual remedies. The exact consequences depend on the purchase contract and circumstances.

Deposit, Reservation Fee and Holding Deposit

Several payments may be described as a deposit, but they are not interchangeable.

Payment	Purpose	Key Point
Mortgage deposit	Your overall contribution towards the price	Affects the mortgage amount and LTV
Exchange deposit	Secures the purchase contract at exchange	Creates serious consequences if the buyer later defaults
New-build reservation fee	Reserves a particular plot for a limited period	Refund terms depend on the reservation agreement
Modern auction reservation fee	Paid under the auction provider’s reservation agreement	Usually separate from the purchase price and exchange deposit
Traditional auction deposit	Paid when the auction contract becomes binding	Often required immediately after a successful bid

Before paying any reservation fee or auction deposit, buyers should understand whether it forms part of the purchase price, whether it is refundable and what happens if the mortgage or legal checks fail.

Common Deposit Mistakes

Assuming a 5% mortgage deposit means the exchange deposit will automatically be 5%.
Using all available savings for the deposit and leaving nothing for tax or legal costs.
Waiting until exchange day to transfer a large amount.
Failing to disclose that part of the deposit is gifted or borrowed.
Assuming the deposit from a related sale will fully cover the new purchase.
Sending money to bank details received through an unverified email.
Confusing a new-build reservation fee with the exchange deposit.
Believing that paying a reduced exchange deposit always limits liability to that amount.
Exchanging before the mortgage offer and deposit arrangements are confirmed.

Deposit Checklist Before Exchange

Confirm the Amount

Check your total mortgage deposit.
Check the exchange deposit stated in the contract.
Ask whether a reduced exchange deposit has been agreed.
Confirm any remaining contribution due before completion.

Prepare the Money

Make sure the deposit is in an accessible account.
Check your bank’s daily transfer limit.
Complete gifted-deposit documents.
Allow time for Lifetime ISA or investment withdrawals.
Provide source-of-funds evidence promptly.

Check Before Sending

Verify the conveyancer’s bank details independently.
Use your property reference when instructed.
Send a small test payment if agreed with the conveyancer.
Keep the transfer confirmation.
Confirm that the conveyancer has received cleared funds.

Frequently Asked Questions

Is the exchange deposit an extra cost?

No. It forms part of the property’s agreed purchase price. It is deducted from the amount that remains payable on completion.

Can I exchange with a 5% deposit?

Possibly, but the seller must normally agree to the reduced amount. Your conveyancer should arrange this before exchange and explain any continuing liability under the contract.

Does the mortgage lender pay the exchange deposit?

Normally no. Mortgage funds are usually released shortly before completion, not exchange. The exchange deposit generally comes from the buyer’s own funds or from a deposit passed up a property chain.

Can my parents pay the exchange deposit?

A family gift may be accepted, but it must be disclosed. The lender and conveyancer will normally require gifted-deposit and source-of-funds evidence.

Can I borrow the exchange deposit?

Borrowed funds may affect mortgage affordability and must not be presented as savings or a gift. The mortgage lender must accept the source and repayment commitment.

What if my sale deposit is smaller than my purchase deposit?

Your conveyancer may request a top-up from you or ask the seller to accept the smaller deposit. This must be agreed before exchange.

When do I pay the remainder of my deposit?

Any part of your total contribution not used at exchange is normally transferred to your conveyancer before completion, together with the other money shown on the completion statement.

Mortgage Deposit vs Exchange Deposit Explained