{"uid":"cap_nSKeVJhK62sk8L1FNafBX","slug":"uk-mortgage-payment-calculator-38d41823","name":"UK Mortgage Payment Calculator","description":"UK mortgage payment calculator: monthly payment, total interest, LTV, repayment or interest-only.","url":"https://finance.payapi.market/mortgage-calculator","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"deposit":{"type":"number","minimum":0,"description":"Deposit in GBP."},"term_years":{"type":"integer","maximum":40,"minimum":1,"description":"Mortgage term in years."},"interest_rate":{"type":"number","description":"Annual interest rate (percent).","exclusiveMinimum":0},"property_price":{"type":"number","description":"Property price in GBP.","exclusiveMinimum":0},"is_interest_only":{"type":"boolean","description":"Interest-only vs. repayment mortgage."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Rcmla4w5aJNp2tf-Pbz4v","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates monthly mortgage payments, total interest, and LTV ratio for UK properties under repayment or interest-only terms.","exampleAgentPrompt":"Can you work out my monthly mortgage payments on a £450,000 property with a £90,000 deposit, a 4.75% annual interest rate, over 25 years on a repayment mortgage?","exampleUseCases":[{"title":"First-time buyer affordability check","prompt":"I'm looking at a £320,000 flat and have saved £32,000 as a deposit. With interest rates at 5.2%, what would my monthly repayment mortgage payments be over a 30-year term, and what's my LTV?"},{"title":"Buy-to-let interest-only cost estimate","prompt":"I want to buy a £500,000 rental property with a £150,000 deposit at 4.9% interest. Can you calculate the monthly cost if I take it as an interest-only mortgage over a 20-year term?"},{"title":"Remortgage comparison at new rate","prompt":"My house is worth £600,000 and I have £240,000 left on the mortgage. If I remortgage at 3.8% over 15 years on a repayment basis, what will my new monthly payments and total interest be?"}],"resultDescription":"Returns the calculated monthly mortgage payment in GBP, total interest payable over the full term, the loan-to-value (LTV) percentage, and the total repayment amount, based on the provided property price, deposit, interest rate, term, and mortgage type.","failureModes":["Missing required field (property_price, interest_rate, or term_years) returns a validation error","interest_rate of 0 or below is rejected due to exclusiveMinimum constraint","term_years outside 1–40 range returns a validation error","Deposit exceeding property price may return an error or zero-loan result","Non-numeric or malformed input values return a 400-level error"],"whenToPreferThis":"Choose this endpoint when you need a quick, accurate UK mortgage cost calculation without building the amortisation logic yourself. It's especially useful for agents helping users evaluate property affordability, compare mortgage scenarios, or understand LTV ratios in the UK market. Prefer this over generic financial calculators when you specifically need GBP-denominated repayment and interest-only comparisons with LTV output.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-16T06:32:31.480Z","isFirstParty":false}