# UK Mortgage Payment Calculator

> UK Mortgage Payment Calculator is a paid API for AI agents from finance.payapi.market, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-16).

Calculates monthly mortgage payments, total interest, and LTV ratio for UK properties under repayment or interest-only terms.

## Facts

- Endpoint: POST https://finance.payapi.market/mortgage-calculator
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/uk-mortgage-payment-calculator-38d41823
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nSKeVJhK62sk8L1FNafBX

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability uk-mortgage-payment-calculator-38d41823 -d '<json body>'
```

Example prompt: 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?

## When to prefer this

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.

## Known failure modes

- 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

## How this service works

UK mortgage payment calculator: monthly payment, total interest, LTV, repayment or interest-only.

## Output

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.

## Request schema (JSON Schema)

```json
{
 "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."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/uk-mortgage-payment-calculator-38d41823/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from finance.payapi.market](https://www.zero.xyz/host/finance.payapi.market/llms.txt)