Definition
A lender may model higher interest, committed spending and foreseeable changes rather than assessing only today's payment. The approach varies by lender, mortgage type, fixed period and applicant. Buy-to-let rental stress testing is a separate calculation based on rent and stressed interest.
Practical example
Two lenders can offer different amounts from the same income because their expenditure assumptions and stress methods differ.
Why it matters
An online income multiple is not a lending decision and can overstate what is affordable.
Mortgage affordability calculatorSource and review
Reviewed 16 July 2026. Product criteria and rules can change.
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