UK buy-to-let mortgage guide

Buy-to-Let Mortgage Guide 2026

Rates, criteria, stress testing, limited company BTL and portfolio landlord rules — everything UK landlords need to know.

How buy-to-let mortgages work

Buy-to-let mortgages are assessed differently from residential mortgages. Lenders focus primarily on the rental income the property will generate rather than your personal income, although personal income still plays a role in affordability assessments.

Stress testing

Lenders typically require the monthly rent to cover 125-145% of the mortgage payment at a stressed interest rate (usually 5-6%). This protects you and the lender if rates rise.

Deposit requirements

Most buy-to-let mortgages require a 25% deposit minimum. Some lenders offer 20% for the right borrower but rates are higher.

Limited company BTL

Purchasing through a limited company keeps mortgage interest fully deductible against corporation tax, avoiding the Section 24 restrictions on individual landlords. More lenders now offer this.

Portfolio landlord rules

Landlords with 4 or more mortgaged properties are classified as portfolio landlords. Lenders assess the entire portfolio, not just the property being mortgaged — more documentation required.

Fixed vs tracker rates

Fixed rates give certainty but tracker rates can be cheaper if rates fall. The spread between them has narrowed significantly in 2026. Your broker can model both scenarios.

Remortgaging

Review your BTL mortgage every 2-3 years or when your current deal expires. Significant savings can be made by switching to a more competitive product.

Speak to a whole-of-market BTL broker

We can refer you to a specialist buy-to-let mortgage broker with whole-of-market access including exclusive rates not available direct. Portfolio landlords and limited company purchases welcome.

Enquire about BTL mortgages

FAQs

Can I get a BTL mortgage with no income?

Most lenders require a minimum personal income of £25,000 alongside rental income. Some specialist lenders will consider rental income only for experienced landlords.

Can I live in my buy-to-let property?

No — buy-to-let mortgages prohibit the owner from living in the property. You would need to remortgage to a residential product first.

Is it better to buy as a limited company?

For higher rate taxpayers it often is, because Section 24 restricts mortgage interest relief for individuals. However, extracting profits from a company via dividends has its own tax implications. Take specialist advice for your situation.

What is the minimum deposit for a BTL mortgage?

Usually 25%, although some lenders offer 20% with higher rates. HMO and multi-unit properties typically require 30-35%.

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