First-Time Buyer Mortgage Debt Simulator

Affordability & Rules

Rule Caps:

Annual Buyer Income £65,000

Gross verified annual household income

Target Property Price £320,000

Agreed purchase price for first-time home

Cash Deposit Percentage 10%

Down payment: £32,000 (Loan-to-Value: 90%)

Mortgage Interest Rate 4.50%

Initial fixed or variable annual rate

Loan Term 30 Years

Extended terms compress monthly payments but expand interest

Regulatory LTI Cap Multiplier 4.50x

Bank of England / PRA macroprudential limit

Maximum LTV Cap 90%

Prudential ceiling on loan relative to valuation

Affordability Verdict & Risk Posture High Leverage

Loan Required

£288,000

Deposit: £32,000

Monthly Payment

£1,459.20

Principal & Interest

Debt-To-Income (DTI)

26.9%

Share of gross income

Max Allowed By LTI

£292,500

Based on 4.5x cap

Total Lifetime Repayment: £525,313.20 Total Interest: £237,313.20

Principal: £288,000

Interest Cost: £237,313.20

Interest Rate Stress-Test (Shock Scenarios)

How monthly debt service responds if base rate adjustments increase borrowing costs:

Rate Environment	Effective Rate	Monthly Payment	DTI Ratio	Delta / Month