Mortgage guide
Buy-to-let mortgages explained
A buy-to-let mortgage is designed for property that will be rented to tenants rather than occupied as your main home. Lenders assess these mortgages differently from ordinary residential borrowing, with expected rental income playing an important role.
The basics
Buy-to-let lending is designed around a property being let.
MoneyHelper explains that buy-to-let mortgages are for properties bought to rent out. They differ from residential mortgages because the lender will normally consider the expected rental income as part of its assessment.
Lender criteria vary and can include minimum income requirements, property type restrictions, landlord experience and limits on the number of mortgaged properties.
If circumstances change and you want to let a home that has a residential mortgage, speak to the lender about consent to let or an appropriate mortgage arrangement.
Rental affordability
The expected rent usually needs to support the mortgage under the lender's calculation.
Buy-to-let lenders commonly use a rental-interest-cover calculation, often called an Interest Coverage Ratio or ICR. This compares expected rent with a stressed mortgage interest cost.
The required percentage and stress rate differ between lenders and can also depend on the applicant's tax position, mortgage type and circumstances.
Allow for void periods, late payments and costs that continue even when the property produces no rental income.
Deposit & LTV
Buy-to-let commonly requires more equity than a residential purchase.
MoneyHelper notes that buy-to-let mortgages generally require a larger deposit than standard residential mortgages. The precise minimum depends on the lender, property and product.
A lower loan-to-value can widen the available product range, but affordability and property criteria still apply.
Repayment method
Many buy-to-let mortgages are arranged on an interest-only basis.
With interest-only borrowing, monthly mortgage payments generally cover interest rather than reducing the original capital. The outstanding loan therefore needs to be repaid separately at the end of the term.
Interest-only
Can reduce the contractual monthly mortgage payment, but the original capital remains outstanding.
Repayment
Payments include capital and interest, so the balance reduces over the term if required payments are maintained.
Interest-only should not be confused with the property paying for itself automatically. The investor still carries the risk that rent, property value or the eventual repayment strategy does not perform as expected.
Regulatory position
Not every buy-to-let mortgage has the same regulatory status.
The FCA states that most buy-to-let lending is not regulated in the same way as residential owner-occupier mortgages. However, certain arrangements can fall within the regulated framework, including some consumer buy-to-let circumstances.
Do not assume every landlord mortgage is either regulated or unregulated purely because the property will be rented out.
Costs & tax
Look beyond the mortgage rate when assessing a rental property.
Mortgage costs
Product fees, valuation charges, legal costs and early repayment charges can apply.
Property costs
Maintenance, safety requirements, insurance, letting-agent fees and periods without a tenant can reduce net income.
Purchase tax
Higher rates of Stamp Duty Land Tax can apply to additional residential properties in England and Northern Ireland, subject to current rules and circumstances.
Income & gains
Rental profit can be taxable and a later disposal can have Capital Gains Tax implications. Tax treatment depends on ownership and individual circumstances.
Tax rules for individual landlords and companies differ, and tax legislation changes. Tax advice may therefore be needed alongside mortgage advice.
You remain responsible for the mortgage even if the property is empty or the rent does not cover all of your costs.
Buy-to-let mortgage advice
Buying or refinancing a rental property?
We can review the borrowing requirement, expected rent, lender criteria, repayment structure and mortgage costs as part of the financing decision.
Book a conversationThis guide is for general information only and is not personal mortgage, investment, tax or legal advice. Buy-to-let mortgage regulation varies by circumstances, and tax treatment depends on individual circumstances and can change. Property values and rental income are not guaranteed. Your property may be repossessed if you do not keep up repayments on your mortgage. Content checked against current FCA, GOV.UK and MoneyHelper guidance on 16 September 2026.