What is a BTL stress test?

Buy-to-let lenders check the rent covers the mortgage interest at a stressed (higher) rate by an interest coverage ratio — typically 125% for basic-rate or company borrowers and 145% for higher-rate taxpayers. If the rent falls short they’ll lend less.

What stress rate should I use?

Lenders commonly stress around 5.5%, or the pay rate plus 2%, though five-year fixes are sometimes stressed at the pay rate. Use your lender’s figure — this tool defaults to 5.5% as a sensible benchmark.

What is a BTL stress test?

Buy-to-let lenders check the rent covers the mortgage interest at a stressed (higher) rate by an interest coverage ratio — typically 125% for basic-rate or company borrowers and 145% for higher-rate taxpayers. If the rent falls short they’ll lend less.

What stress rate should I use?

Lenders commonly stress around 5.5%, or the pay rate plus 2%, though five-year fixes are sometimes stressed at the pay rate. Use your lender’s figure — this tool defaults to 5.5% as a sensible benchmark.

BTL Mortgage Stress Test

Will the rent pass the lender’s test? Check your rent against the stressed interest and coverage ratio, and see the most you could borrow.

Monthly rent

Mortgage loan amount

Stress test rate

Interest coverage ratio

PASSES STRESS TEST

At 5.5% and 145% ICR the lender needs £997/month; you have £1,000 (100% of the requirement).

Required monthly rent

£997

Rent coverage

100%

Max borrowing on this rent

£150,470

This calculator is for guidance only and does not constitute financial, tax, mortgage or investment advice. Figures are estimates — always seek professional advice and verify costs before committing to a purchase.

BTL stress test — common questions

What is a BTL stress test?: Buy-to-let lenders check the rent covers the mortgage interest at a stressed (higher) rate by an interest coverage ratio — typically 125% for basic-rate or company borrowers and 145% for higher-rate taxpayers. If the rent falls short they’ll lend less.
What stress rate should I use?: Lenders commonly stress around 5.5%, or the pay rate plus 2%, though five-year fixes are sometimes stressed at the pay rate. Use your lender’s figure — this tool defaults to 5.5% as a sensible benchmark.

BTL Mortgage Stress Test

BTL stress test — common questions

Turn these numbers into an investor-ready pack