Explore how the UK tax system works today — and model what a fairer one could look like. Move the sliders. See who pays, who benefits, and what it funds.
This tool is designed to make the UK tax debate accessible and evidence-based. All figures are estimates drawn from published academic and policy modelling — the sources and methods are set out below.
Wealth-tax yields draw on the Wealth Tax Commission; effective-rate curves on Advani and Summers, LSE; property-tax modelling on the AJS Fairer Property Tax paper, IFS land value tax research, and HMT Budget 2025 High Value Council Tax Surcharge documentation; Tax Policy Associates; poverty and Gini baselines on ONS and IFS. Behavioural-response modelling for the wealth levy draws on CenTax qualitative research on mobility of high-wealth individuals, the Wealth Tax Commission Final Report 2020 behavioural response modelling, Henley and Partners' updated migration methodology statement, and contested Norwegian wealth tax departure evidence — see academic literature. Note that the Henley and Partners data underpinning most millionaire exodus headlines has been substantially revised and should not be treated as reliable evidence of tax-driven migration.
The wealth-levy revenue model applies user-selected marginal rates to illustrative tax bases in each band, calibrated so that 1% above £10m yields approximately £10bn, consistent with Wealth Tax Commission modelling. CGT reform scales the current approximately £15bn yield across basic and higher band gains with a modest behavioural haircut above 30%. Income tax and National Insurance uplifts use IFS-style yields for threshold and rate changes. Property-tax modelling assumes approximately 28 million residential properties, split between values up to and above £500,000, net of the current approximately £25bn Council Tax yield.
Poverty and inequality indicators show directional movement only. They are not precise forecasts. Actual outcomes depend on behavioural responses, implementation design, and wider economic conditions.
Real world impact return rates of 3%, 5%, and 7% are based on long-run average returns for diversified investment portfolios. The 5% nominal central estimate is consistent with AJS Fair Contribution paper assumptions and Wealth Tax Commission modelling. Individual returns vary by asset class, year, and portfolio composition.
Estimates of the number of people affected at each wealth tax threshold are drawn from the following sources. The £50m threshold figure of approximately 5,000 people is sourced from Tax Policy Associates, drawing on Wealth Tax Commission distributional data. The £10m threshold figure is disputed between sources — Oxfam, Patriotic Millionaires UK and Tax Justice UK estimate approximately 20,000 people; Tax Policy Associates estimates approximately 32,000. The difference reflects different approaches to measuring net wealth at the top of the distribution and the absence of reliable official data at this level. The £5m threshold figure is an extrapolation from these sources and should be treated as an illustrative estimate only. The absence of a reliable official count of individuals above these thresholds is itself one of the strongest arguments for the national wealth register proposed in the AJS Fair Contribution paper.
The departure rate slider range and default position vary by threshold to reflect the different evidence bases for wealth flight at each level. At £50m the range extends to 30% reflecting the genuine mobility of this cohort and the stronger evidence for departure at this level. At £10m the range is capped at 20% consistent with the Wealth Tax Commission central estimate and CenTax qualitative findings that tax is rarely the primary driver of relocation. At £5m the range is capped at 15% and figures are illustrative extrapolations given the thinner evidence base and the greater illiquidity of wealth typically held at this level. All departure rate estimates should be treated as illustrative scenarios rather than precise forecasts. Sources: Wealth Tax Commission Final Report 2020; CenTax qualitative research on mobility of high-wealth individuals 2024; Tax Policy Associates, UK wealth tax analysis 2025; Henley and Partners updated migration methodology statement — note that Henley and Partners data underpinning most millionaire exodus headlines has been substantially revised and should not be treated as reliable evidence of tax-driven migration.
Income tax figures apply to England only. Scottish rates differ. Wealth levy and distributional figures apply UK-wide.
The contextual explanation of higher effective rates at the top is drawn from published academic research and the liberal political philosophy underpinning AJS policy. It is provided as factual context, not political advocacy.