Specialist Finance

Buy-to-Let

Residential investment property mortgages for individual landlords and portfolio investors, with products tailored to your investment strategy.

80%
Max LTV
125%
Min ICR
5-25yrs
Terms
48hrs
Decision
60+ BTL Lenders
Portfolio Specialists
Ltd Company Experts

The Complete Guide to Buy-to-Let Mortgages in the UK

Buy-to-let mortgages are specialist property loans designed for landlords purchasing residential properties to rent out to tenants. Unlike standard residential mortgages, BTL lending is assessed primarily on the rental income the property generates rather than the borrower's personal earnings, making them accessible to investors regardless of employment status.

The UK buy-to-let market has evolved significantly following regulatory changes, with lenders applying stricter affordability tests and portfolio landlord rules. However, opportunities remain strong for well-prepared investors who understand the lending landscape and structure their investments appropriately.

Whether buying your first rental property or expanding a portfolio of dozens, understanding how BTL mortgages work is essential for maximising returns. From stress testing to limited company structures, ICR calculations to portfolio landlord rules, this guide covers everything you need to know.

UK Market Overview (2024-2025)

Typical interest rates:4.5% - 7% p.a.
Maximum LTV:75-80%
Minimum ICR:125% at 5.5% stress
Minimum deposit:20-25%
Average UK yield:5.5%
Portfolio threshold:4+ mortgaged properties

How Buy-to-Let Works

1

Interest Cover Ratio (ICR)

Lenders require rental income to cover mortgage payments by 125-145%, calculated at a "stressed" rate (typically 5.5%+). Higher rate taxpayers often face 145% requirement.

2

Stress Testing

Since 2017, lenders stress test at elevated rates to ensure landlords withstand rate rises. This affects maximum borrowing regardless of actual rate secured.

3

Personal vs Company

Personal ownership is simpler but mortgage interest relief is restricted. Limited company (SPV) ownership allows full interest deduction against corporation tax—more tax-efficient for higher-rate taxpayers.

When to Use Buy-to-Let

Understanding the right scenarios ensures you're using this finance type strategically.

Standard Buy-to-Let

Single let properties rented to one household under AST. Most common BTL type with widest lender choice and best rates.

  • Houses, flats, bungalows
  • Single AST tenancy
  • Most lender options
  • Best rates available

Portfolio Landlord

For landlords with 4+ mortgaged properties. Requires full portfolio assessment but specialist lenders offer flexibility.

  • 4+ mortgaged properties
  • Full portfolio stress test
  • Specialist lenders
  • Competitive rates

Limited Company BTL

Properties held in SPV or trading company. Tax efficiency benefits for higher-rate taxpayers building portfolios.

  • Corporation tax rates
  • Full interest relief
  • Slightly higher rates
  • Tax planning benefits

Holiday Let / Airbnb

Short-term holiday letting rather than AST. Specialist products with higher yield potential but seasonal income considerations.

  • Short-term lets
  • Seasonal income
  • FHL tax rules
  • Limited lender options

Buy-to-Let Costs Explained

Cost ComponentTypical RangeNotes
Deposit20-25%+Best rates at 40%+
Stamp Duty (3% surcharge)3%+ above thresholdsAdditional property surcharge
Mortgage Fees£500 - £2,000Often added to loan
Legal & Survey£1,500 - £3,000Standard conveyancing
Management Fee8-15% of rentIf using letting agent
Maintenance10% of rentPrudent allowance

Our Buy-to-Let Process

1

Property Search

Identify suitable investment property meeting yield requirements and your investment criteria.

2

Mortgage Research

Establish borrowing capacity based on expected rent and your circumstances.

3

Agreement in Principle

Secure AIP from lender to strengthen your purchase position.

4

Full Application

Submit full application with rental assessment and property details.

5

Completion

Complete purchase, set up tenancy, begin generating rental income.

Key Features of Buy-to-Let

Competitive rates from specialist buy-to-let lenders
Personal name and limited company purchase options
Portfolio landlord specialists for multiple properties
Products for first-time landlords with no prior experience
Holiday let and short-term rental mortgages available
5-year fixed rates for long-term investment planning

Who Is Buy-to-Let Ideal For?

First-time landlords entering the property investment market
Portfolio landlords expanding their property holdings
Investors seeking stable long-term rental income
Limited company investors for tax efficiency
Landlords remortgaging to release equity or secure better rates

Buy-to-Let vs Traditional Options

AspectBuy-to-LetAlternative
Income AssessmentBased on rental incomeResidential: personal income
Deposit Required20-25% minimumResidential: 5-10% possible
Stress Testing5.5%+ stress rateResidential: actual rate
Tax TreatmentRestricted interest reliefOwner-occupied: no rental income

Frequently Asked Questions About Buy-to-Let

How much rental income do I need for a buy-to-let mortgage?

Most buy-to-let lenders require rental income to be 125-145% of the mortgage payment, calculated at a notional interest rate (typically 5.5-6%). This is called rental coverage or interest coverage ratio. For example, if your mortgage payment at the stress rate is £1,000, you'd need monthly rent of £1,250-£1,450. Portfolio landlords and higher rate taxpayers often face higher coverage requirements (up to 145%).

Should I buy in my personal name or a limited company?

This depends on your tax position. Since 2017, tax relief on mortgage interest has been restricted for personal landlords, making limited company ownership more tax-efficient for higher rate taxpayers. However, limited company mortgages often have slightly higher rates and fees. For basic rate taxpayers or those with only 1-2 properties, personal ownership may be simpler. We recommend speaking with an accountant about your specific situation.

Can I get a buy-to-let mortgage with no landlord experience?

Yes, many lenders offer products for first-time landlords. You'll typically need a larger deposit (usually 25% minimum) and may face slightly higher rates. Some lenders also cap the property value or number of properties they'll finance for inexperienced landlords. Having homeowner experience and a strong credit history helps significantly. Certain property types (ex-council, studio flats) may be restricted for novice landlords.

What is a portfolio landlord and how does it affect lending?

The PRA defines a portfolio landlord as someone with four or more mortgaged buy-to-let properties. Portfolio landlords face additional underwriting scrutiny, with lenders assessing your entire property portfolio, not just the individual application. You may need to provide full portfolio details, rental income evidence, and stress testing across all properties. However, specialist portfolio lenders offer better service and more flexibility for experienced investors.

How much deposit do I need for a BTL mortgage?

Minimum 20-25%, compared to 5-10% for residential. Best rates at 40%+ deposits (60% LTV or lower). HMOs and multi-units often require 25-30%. Some lenders offer 80% LTV but with stricter ICR requirements.

Can I get a BTL mortgage as a first-time buyer?

Yes, but options are more limited. Some lenders exclude first-time buyers from BTL. You won't benefit from FTB stamp duty relief and will pay the 3% surcharge. Having 25%+ deposit and clear investment rationale improves chances.

Should I buy in personal name or limited company?

Depends on tax position. Personal ownership is simpler but interest relief restricted to basic rate. Limited company allows full interest deduction against corporation tax. Higher-rate taxpayers building portfolios typically favour company; basic rate taxpayers with 1-2 properties often stay personal.

What happens when I have 4+ mortgaged properties?

You become a "portfolio landlord" with enhanced underwriting. Lenders assess your entire portfolio's stress-tested affordability. You need full details of all properties. Specialist portfolio lenders often offer better terms for experienced investors.

Why Choose CMB for Buy-to-Let?

Specialist Expertise

Dedicated buy-to-let specialists with deep market knowledge.

100+ Lenders

Access to an extensive panel of specialist lenders.

NACFB Member

Adhering to strict professional and ethical standards.

£1BN+ Arranged

Proven track record in property finance.

Ready to discuss your buy-to-let needs?

Speak with our specialist team today and get a decision in principle within 48 hours.