How much deposit do you need for a buy-to-let mortgage?

How much deposit do you need for a buy-to-let mortgage?

For most landlords, the deposit is one of the biggest moving parts when planning a buy-to-let purchase. In general, buy-to-let mortgages tend to require a larger deposit than residential mortgages, because lenders assess rental income and the overall risk of the investment.

The exact deposit you’ll need depends on factors such as the property type, your experience as a landlord, the lender’s criteria, and how your application is structured.

Where is your buy-to-let deposit likely to come from?

Lenders will usually want evidence of the source of funds. Common sources include:

• Personal savings and investments
• Gifts
• Inheritance
• Sale of a property
• Sale of other assets
• Unsecured borrowing (where permitted)
• Deposit from overseas (where permitted)
• Other documented sources

If you’re planning to use a gifted deposit or funds from another property, it’s helpful to ensure the paperwork is clear and traceable.

Typical buy-to-let deposit levels (what many landlords plan for)

While every lender is different, a common starting point is that many buy-to-let mortgages are offered with deposits in the region of 20% to 40% of the property value. Around 25% is often seen as a practical benchmark.

You may be asked for a higher deposit if:

• The lender views the deal as higher risk
• The property is a flat, maisonette, or has characteristics that affect rental demand
• The purchase is a new build (some lenders apply tighter criteria)
• Your application profile doesn’t match the lender’s preferred customer profile

In practice, the smaller the deposit, the more limited the lender choice can become.

Minimum deposit requirements: what’s possible?

Some lenders may consider deposits lower than 20%, but these cases are not the norm and will depend heavily on the rest of your application.

Deposits below 10% are not impossible in every market, but they are typically more difficult to secure and usually require strong compensating factors (such as robust rental income, strong landlord experience, or other application strengths).

Can you get a 100% LTV buy-to-let mortgage?

In most cases, buy-to-let mortgages still require a deposit. A 100% LTV approach is generally not available for buy-to-let lending in the same way it may be for some residential products.

It’s also important to remember that the deposit is only one part of the upfront picture. Other costs—such as legal fees, surveys, potential renovation, and early letting/management expenses—can affect how much cash you need before the property becomes income-producing.

How deposit size affects the mortgage you’re offered

Deposit size is closely linked to the loan-to-value (LTV) ratio. As LTV increases (meaning the deposit is smaller), lenders may:

• Offer fewer product options
• Apply higher interest rates
• Require additional conditions or stronger evidence of affordability and rental performance

This doesn’t mean a low-deposit application is automatically unsuitable, but it does mean the lender’s risk assessment becomes more significant.

Property type and deposit expectations

Lenders often treat different property types differently. As a general guide:

• Houses may have more competitive options at certain LTV levels
• Flats and maisonettes can face tighter criteria, particularly where rental demand or resale considerations are more variable
• New builds may be subject to additional scrutiny depending on the lender’s approach to construction, valuation, and rental assumptions

Because of this, the deposit you need can vary even when the property value is the same.

Strategies to consider if you’re aiming for a lower deposit

If you’re working with a smaller deposit, the goal is usually to improve the overall strength of the application so it fits the lender’s risk appetite.

Common approaches include:

• Increase the deposit where possible: even a modest increase can improve LTV and widen the range of lenders/products.
• Choose the right property: property type and location can influence how lenders assess rental prospects.
• Strengthen the application package: clear documentation, realistic rental assumptions, and well-prepared business information can matter when deposit options are limited.
• Consider refinancing after purchase (where appropriate): some landlords plan to remortgage later if their LTV improves, but the timing and options depend on lender criteria and the mortgage terms.

What evidence do lenders expect for the deposit?

Most lenders will want proof of the source of funds. The level of documentation can vary, but it often includes:

• Bank statements showing savings accumulation
• Evidence for gifted funds (and confirmation of the gift nature)
• Sale completion documents for proceeds from property sales
• Statements and paperwork for investments or other assets
• Documentation for any borrowing used as part of the deposit (where permitted)

Having clear evidence can reduce delays and help ensure the application is assessed smoothly.

Deposit and the wider buy-to-let affordability picture

Even if deposit size is your main focus, buy-to-let lending is typically assessed using more than just LTV. Lenders also consider rental income and whether it meets their required coverage.

That means a larger deposit can help you access more options, but a strong rental case can also be important—particularly when you’re aiming for a lower deposit.

Using a buy-to-let deposit calculator (to sense-check your numbers)

A calculator can help you understand how changing the deposit affects the loan amount and, in turn, the monthly repayments.

When using a buy-to-let mortgage calculator, it’s useful to input:

• Property value
• Deposit amount
• Anticipated monthly rent
• Interest rate (based on the product you’re considering)
• Mortgage term

This won’t replace lender assessment, but it can help you compare scenarios and plan the cash you’ll need.

Key takeaways

• Many buy-to-let mortgages are commonly planned with deposits around 20% to 40%, with 25% often a practical benchmark.
• Lower-deposit options can exist, but lender choice may be more limited and the rest of the application needs to be strong.
• The deposit must be supported by clear evidence of source of funds.
• Deposit size influences LTV, which can affect the mortgage rate and product availability.

If you’re comparing options, it’s often worth looking at multiple deposit scenarios alongside the property type and your rental assumptions, so you can understand how the deposit requirement fits into the overall buy-to-let plan.