Buy-to-let mortgage deposits: LTV, rent and examples

Around 25% of the purchase price is a sensible starting point when planning a buy-to-let deposit. On a £250,000 property, that means contributing £62,500 and applying to borrow the remaining £187,500.

However, 25% isn’t a fixed requirement for every application. Some products may permit a smaller deposit, while the expected rent, property valuation and lender’s criteria could mean you need more. Your budget also needs to cover purchase costs and money for unexpected expenses.

What is a typical buy-to-let deposit?

A 25% deposit is a common planning figure for buy-to-let, rather than a universal minimum. It means you fund a quarter of the property’s price and seek a mortgage for the remaining three-quarters.

Your deposit is only one part of how buy-to-let mortgages are assessed. The property, rental income, your circumstances and whether you buy personally or through a company can all affect the application.

The distinction matters: a product’s maximum loan-to-value tells you the smallest deposit it permits, but the lender’s rental assessment may mean you need to contribute more.

How do deposit and loan-to-value work?

Loan-to-value, usually shortened to LTV, is the mortgage expressed as a percentage of the property’s value. A 25% deposit produces a 75% LTV mortgage, assuming the lender accepts the purchase price as the value.

The basic relationship is:

Deposit percentage = 100% minus the mortgage LTV.

For a £250,000 property, the figures would look like this:

Deposit percentage	Cash deposit	Mortgage required	LTV
20%	£50,000	£200,000	80%
25%	£62,500	£187,500	75%
30%	£75,000	£175,000	70%
40%	£100,000	£150,000	60%

These examples show the calculation only. They don’t confirm that a product is available at each LTV or that the rent would support the mortgage. Purchase costs are additional.

If you already know the property value and mortgage amount, our loan-to-value calculator can help you check the percentage.

Can you get a buy-to-let mortgage with less than 25% deposit?

Potentially, depending on current product availability and your application. Higher-LTV options may sometimes allow a smaller deposit, but availability changes.

A smaller deposit means a larger mortgage. That can make the rental assessment harder to satisfy, even where you meet the product’s LTV limit. Rates, fees and eligibility requirements may also differ between LTV bands.

When we assess a lower-deposit application, we would check both whether a suitable product exists and whether the expected rent supports the larger loan. We would also compare the overall costs, rather than choosing a mortgage solely because it requires less cash upfront.

Why might you need a larger buy-to-let mortgage deposit?

Buy-to-let mortgage criteria vary. Circumstances that may reduce lender choice or the amount available include:

• Expected rent that doesn’t support the requested mortgage.
• A specialist property, such as a house in multiple occupation (HMO) or a building containing several rental units.
• Construction or condition that falls outside standard property criteria.
• Credit history that restricts the products available.
• Being a first-time landlord or not already owning a home.
• An ownership structure or loan amount outside a lender’s rules.

None automatically means a larger deposit is required. An HMO mortgage or a buy-to-let mortgage with adverse credit needs to be assessed against the relevant lender’s criteria. Extra cash won’t necessarily resolve an eligibility issue.

What if the valuation is lower than the purchase price?

Suppose you agree to pay £250,000 and plan to put down £62,500, borrowing £187,500. The lender then values the property at £240,000.

If its maximum loan is 75% of that lower valuation, the mortgage would be capped at £180,000, before any other restrictions. To proceed at the same purchase price, you would need £70,000 towards it, which is £7,500 more than planned.

We would recalculate the figures at that point. You may need to contribute more or renegotiate the purchase price.

How can rental income affect the deposit you need?

Lenders commonly assess rental affordability using an Interest Coverage Ratio, or ICR. This compares expected rent with a mortgage-interest amount calculated using a stress rate, which may differ from the rate you actually pay. The required ratio and stress rate vary between lenders, borrowers and products.

The PRA’s buy-to-let underwriting standards set expectations for lenders within their scope to use rental-cover testing, personal-income affordability testing, or both. Property costs and relevant tax liabilities also matter, and expected rent needs suitable verification, such as valuation or tenancy evidence.

Some lenders allow personal income to supplement rent, often called top-slicing. This involves further affordability checks and isn’t available in every case.

When a 25% BTL deposit becomes 30%

Consider this illustrative purchase:

Item	Amount
Purchase price	£250,000
Planned 25% deposit	£62,500
Mortgage requested	£187,500
Maximum loan supported by the rental assessment	£175,000
Deposit needed to cover the difference	£75,000
Deposit as a percentage of the price	30%

Here, the rent limits borrowing to £175,000, even if the product permits 75% LTV. The buyer would need another £12,500 to proceed at the same price with that mortgage. This is an example, not a universal lender calculation.

Our buy-to-let mortgage calculator can help you compare the deposit, loan amount, rental yield and rental cover. Its rental-cover figure uses the interest rate you enter, so it doesn’t confirm that the property passes a lender’s stress test or that you qualify for a mortgage.

Does a limited company need a different BTL deposit?

Not necessarily. Personal and limited-company mortgages can have different product ranges and criteria, but company ownership doesn’t automatically require a larger or smaller deposit.

The deposit is only one part of a limited company buy-to-let mortgage. Lenders may assess the company structure, directors, shareholders, property and rent. Creating a new special purpose vehicle, a company set up for a particular purpose such as holding rental property, doesn’t remove checks on the people behind it.

We wouldn’t suggest choosing an ownership structure solely because one mortgage appears to require less deposit. Mortgage costs and accounting implications need consideration alongside tax advice from a qualified adviser.

Where can a buy-to-let mortgage deposit come from?

Possible sources include savings, proceeds from a property sale, inheritance and gifted funds. A company purchase may use company funds or a director’s loan, subject to the lender’s requirements.

One of the first things we would want to understand is where the money comes from. An acceptable amount still needs an acceptable, properly evidenced source.

A gifted deposit for a buy-to-let mortgage must be disclosed. A non-repayable gift is different from a loan, and lenders may require confirmation of the donor’s relationship to you and whether they expect repayment or an interest in the property.

It may also be possible to release equity for a buy-to-let deposit through additional secured borrowing, including a buy-to-let remortgage on an existing rental property. That borrowing needs its own affordability and cost assessment. It increases your debt, and unsecured borrowing shouldn’t be assumed acceptable.

Company funds and director’s loans may also need accounting or tax advice.

What other costs should you budget for?

The deposit isn’t your total cash requirement. Stamp Duty on a buy-to-let property can be a substantial separate expense, with the amount depending on where the property is:

• Stamp Duty Land Tax in England and Northern Ireland
• Land and Buildings Transaction Tax in Scotland
• Land Transaction Tax in Wales

You should also allow for:

• Mortgage product fees and any mortgage-advice fees.
• Valuation, survey and conveyancing costs.
• Company setup or accountancy costs, where relevant.
• Insurance, licensing and safety work.
• Repairs and preparing the property for tenants.
• Periods without rental income and unexpected bills.

Get estimates for the property you’re considering. A single percentage allowance won’t account for differences in tax, condition and transaction costs.

Is a bigger buy-to-let deposit always better?

A larger deposit reduces the mortgage required. It may help the rental calculation, open different LTV bands and reduce interest costs. Having additional funds available can also help if a valuation comes back lower than expected.

However, putting more into the purchase leaves less for tax, fees, repairs and financial reserves. Moving to a lower LTV doesn’t necessarily produce a proportionate improvement in mortgage terms.

We would compare the products available at different deposit levels alongside the money you would retain. A deposit that uses every available pound could leave you struggling to cover an empty month or an urgent repair.

How to estimate the deposit you may need

1. Confirm the expected purchase price.
2. Calculate 25% as an initial planning figure.
3. Subtract it from the price to find the mortgage required and check the LTV.
4. Obtain a realistic estimate of market rent.
5. Test the figures using our buy-to-let calculator.
6. Check whether the property or ownership structure could restrict lender choice.
7. Budget separately for tax, fees, property work and reserves.
8. Check current lender criteria before making a financial commitment.

This gives you a starting budget. It doesn’t replace a lender’s assessment or a mortgage recommendation.

What we would check before recommending a mortgage

At Monday Mortgages, we would check the purchase price, estimated value, deposit amount and source, mortgage required and expected monthly rent together.

We would also consider the property type, intended tenants, ownership structure, landlord experience and any existing portfolio. Your income, employment, credit history, other borrowing and remaining cash reserves may affect which options are suitable.

If you already have a purchase price, deposit and expected rent, our buy-to-let mortgage advisers can assess how those figures work together and identify options based on the wider application.