Calculate rental yield, cash flow, and return on investment
Good yields: 5-8% gross, 3-6% net (varies by location)
Buy-to-let (BTL) mortgages are specifically designed for properties you intend to rent out rather than live in. They differ from residential mortgages in several key ways: they typically require a larger deposit (usually 25%), charge higher interest rates, and are often arranged on an interest-only basis. Affordability is primarily assessed based on expected rental income rather than your personal salary.
Most BTL lenders require the rental income to cover at least 125% of the mortgage payment at a stress-tested interest rate (typically 5.5%). This is known as the Interest Coverage Ratio (ICR). Higher-rate taxpayers may face a stricter requirement of 145%. Understanding these criteria is essential before committing to a property purchase.
Understanding the tax position is crucial for buy-to-let profitability. Since April 2020, significant changes to mortgage interest tax relief have affected many landlords' bottom lines.
Rental income is added to your other income and taxed at your marginal rate. You can deduct allowable expenses including letting agent fees, maintenance and repairs, insurance premiums, ground rent and service charges, and accountancy fees. However, improvements (such as extensions or upgrades) are not deductible — only repairs that restore the property to its previous condition qualify.
Before 2017, landlords could deduct their full mortgage interest from rental income before calculating tax. Since April 2020, mortgage interest is no longer deductible. Instead, you receive a 20% tax credit on mortgage interest payments. This change has little impact on basic-rate taxpayers but significantly reduces profits for higher-rate (40%) and additional-rate (45%) taxpayers.
Example: A higher-rate taxpayer with £10,000 annual mortgage interest previously saved £4,000 in tax. Under the new rules, they receive a £2,000 tax credit — a £2,000 annual increase in their tax bill.
When you sell a buy-to-let property, you may owe Capital Gains Tax (CGT) on any profit above your annual allowance. The CGT rates for residential property are 18% for basic-rate taxpayers and 24% for higher-rate taxpayers. You must report and pay CGT within 60 days of completion. Allowable deductions include purchase costs, improvement costs, and selling expenses.
Many new landlords are choosing to purchase buy-to-let properties through a limited company (known as a Special Purpose Vehicle or SPV). Companies can still deduct full mortgage interest as a business expense and pay corporation tax (currently 25%) rather than income tax. This can be more tax-efficient for higher-rate taxpayers, though company mortgages may have higher interest rates. Professional tax advice is strongly recommended.
Successful buy-to-let investment depends on choosing the right property in the right location. Consider these factors:
As a landlord in England and Wales, you are legally required to:
Failure to meet these obligations can result in significant fines and may prevent you from evicting tenants. Consider using a reputable letting agent if you are unsure about your legal responsibilities.
Related: Read our buy-to-let investment guide, use our stamp duty calculator to estimate purchase costs, and check LTV requirements.