Learn How Kumberi Models UK Money Decisions
Guides on the UK tax, pension, property and family rules used when you run a life-and-money what-if
Transparent Calculations
See exactly how we model your financial journeys
Start From The Life Question
Guides explain the UK rules. Decision pages start from the choice already in your head — then open a journey that can hold the events after it, year by year.
Browse Life Decisions
How We Calculate Retirement
How Kumberi models UK retirement what-ifs
Retirement Planning in Kumberi
How we model UK state pensions, workplace pensions, and retirement income in your journeys.
UK Pension System
How we calculate state pension, private pensions, and lifetime allowance in your projections.
Tax-Free Lump Sums
How we calculate tax-free pension withdrawals in your journeys.
Withdrawal Rates
How we apply safe withdrawal rate principles (like the 4% rule) to your retirement journeys.
FIRE Strategy Modelling
How we calculate Financial Independence what-ifs and early retirement projections.
Property & Mortgage Calculations
How we model property and mortgage what-ifs
Mortgage Overpayments
How we calculate interest savings and term reductions when you overpay your mortgage.
Remortgaging Scenarios
How we model remortgaging costs, savings, and timing in your journeys.
Early Repayment Charges
How we calculate ERCs when modelling early mortgage repayments.
Shared Ownership
How shared ownership, staircasing and rent on the unsold share work — use the mortgage calculator; this is not yet inside a journey.
Investment And ISA Modelling
How we calculate investment growth and tax
Company Car & Benefits Calculations
How we calculate employment benefits tax
Benefit in Kind (BiK)
How we calculate company car tax and BiK charges in your journeys.
P11D Values
How we calculate P11D values for company benefits.
Electric Vehicle Benefits
How we calculate BiK for electric company cars and their tax advantages.
EV vs Hybrid Comparison
How we model the cost comparison between electric and hybrid company cars.
Class 1A National Insurance
How we calculate employer NI contributions on benefits in kind.
Salary Sacrifice
How we model salary sacrifice schemes and their tax/NI benefits.
Tax & Student Loan Calculations
How we apply UK tax rules
Ltd Company
How we model director extraction and loan credit
Family & Childcare
How we apply free hours and Tax-Free Childcare
Our Calculation Methodology
Complete transparency on our calculations
Illustrative UK Decision Tools
Mortgage, company-car and salary-versus-dividend illustrations using the same UK rules as a modelled journey
Mortgage Calculator
Monthly payments, overpayment impacts, and different mortgage options for a property decision.
Car Cost Comparison
Model personal purchase or lease costs, or a company car’s Benefit in Kind. Illustrative figures using current UK rates — not a recommendation.
Open The Car ToolReady To Model Your Next Decision?
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