Losing too many of the top earners would be catastrophic for the UK

The Risks of a Tax System Increasingly Funded by a Small Minority

The United Kingdom’s tax system is often described as progressive, meaning those with the highest incomes contribute a greater proportion of their earnings in tax than those on lower incomes. What is less widely appreciated, however, is just how heavily the country’s public finances depend upon a relatively small number of taxpayers.

According to the latest figures published by HM Revenue & Customs (HMRC), Income Tax receipts are now extraordinarily concentrated among the nation’s highest earners. While political debate frequently focuses on whether the wealthy should pay more tax, the official statistics reveal that a relatively small group already funds a substantial proportion of government revenue collected through Income Tax.

The question policymakers should be asking is not simply how much these individuals contribute, but what would happen if a significant number of them chose to leave the United Kingdom.

The Numbers Behind Britain’s Tax Base

There are approximately 34.5 million Income Tax payers in the UK.

Of these:

• The top 10% of taxpayers earn approximately £67,400 or more per year.
• The top 1% of taxpayers earn approximately £201,000 or more per year.

HMRC’s data shows that the top 10% of taxpayers account for 60.3% of all Income Tax liabilities, while the top 1% alone account for 28.5%.

In monetary terms, total Income Tax liabilities for the most recent tax year amounted to approximately £245 billion.

This means:

Top 10% of Taxpayers

• Number of taxpayers: approximately 3.45 million
• Share of all Income Tax: 60.3%
• Total Income Tax paid: approximately £147.7 billion annually

Top 1% of Taxpayers

• Number of taxpayers: approximately 345,000
• Share of all Income Tax: 28.5%
• Total Income Tax paid: approximately £69.8 billion annually

Put another way, just 345,000 individuals contribute almost £70 billion in Income Tax each year—more than a quarter of all Income Tax collected by the Treasury.

Why Is the Burden So Concentrated?

Several factors contribute to this concentration.

Firstly, the UK operates a progressive Income Tax system. Higher earners move into the 40% higher-rate tax band and the 45% additional-rate band.

Secondly, the withdrawal of the Personal Allowance between £100,000 and £125,140 creates one of the highest effective marginal tax rates in the developed world. Within this range, taxpayers effectively face a 60% Income Tax rate because every additional £1 earned not only attracts tax but also results in the loss of tax-free allowance.

Thirdly, income itself is increasingly concentrated. Estimates suggest the top 1% of earners receive around 12% to 15% of all pre-tax income in the UK.

Finally, a substantial proportion of adults earn too little to pay Income Tax at all. As a result, the responsibility for funding Income Tax revenues falls increasingly on those at the upper end of the income distribution.

What If 25% of the Top 10% Left Britain?

Suppose just one-quarter of the top 10% of taxpayers decided to relocate abroad.

This would represent approximately 862,500 individuals.

Assuming their Income Tax contributions were lost entirely, the Treasury would forgo around:

£36.9 billion per year

This is equivalent to approximately 15% of all Income Tax revenue currently collected by the Government.

To put that figure into context, £36.9 billion exceeds the annual budgets of several major government departments and is greater than the cost of many large national infrastructure programmes.

Replacing such a shortfall would likely require a combination of higher taxes elsewhere, increased borrowing, reductions in public spending, or some combination of all three.

What If 25% of the Top 1% Left Britain?

The impact becomes even more striking when focusing solely on the highest earners.

If just one-quarter of the top 1% left the country, that would involve approximately 86,250 individuals.

The potential loss in Income Tax revenue would be:

£17.4 billion per year

This represents around 7% of all Income Tax receipts.

In practical terms, a loss of this magnitude would create a significant hole in the public finances that would need to be addressed through alternative taxation, spending cuts, or increased government borrowing.

The Real Cost Could Be Much Higher

The figures above only consider Income Tax.

In reality, many members of the top 1% are not merely employees earning large salaries. They are often entrepreneurs, company founders, investors, senior executives, medical specialists, financial professionals, and business owners.

If substantial numbers were to leave the UK, the economic consequences could extend far beyond lost Income Tax receipts.

Additional losses could include:

Capital Gains Tax

High earners account for a disproportionate share of investment gains and business disposals.

Corporation Tax

Entrepreneurs frequently establish and manage businesses where they reside. Relocation can influence where future investment and growth take place.

VAT Revenue

Higher-income households typically spend more money, generating greater VAT receipts.

Stamp Duty

Property transactions at the upper end of the housing market contribute significant amounts in Stamp Duty Land Tax.

Investment in New Businesses

Many start-ups and growing companies depend upon angel investors and wealthy entrepreneurs for funding.

Employment

Business owners and investors support large numbers of jobs directly and indirectly throughout the economy.

Consequently, the broader economic effect of large-scale departures among top earners could exceed the headline Income Tax losses by a considerable margin.

A Delicate Balance

It is important to note that these scenarios are hypothetical. Not everyone who relocates ceases all UK tax activity, businesses do not automatically disappear, and some economic activity would remain within the country.

Equally, new taxpayers and businesses may arrive to offset part of any losses.

Nevertheless, the official statistics reveal an undeniable reality: Britain’s public finances have become highly dependent upon a relatively small group of high-income individuals.

Just 3.45 million taxpayers—the top 10%—contribute approximately £147.7 billion in Income Tax, while only 345,000 taxpayers—the top 1%—contribute almost £70 billion.

This concentration creates both a strength and a vulnerability. The strength lies in the ability of the tax system to raise substantial revenue from those with the greatest capacity to pay. The vulnerability lies in the growing dependence upon a comparatively small number of individuals whose decisions about where to live, work, invest and build businesses can have an outsized impact on the nation’s finances.

Whether one views this as evidence of fairness, success, or excessive dependence is ultimately a matter of political opinion. The numbers themselves, however, are not in dispute. Britain’s tax system is increasingly reliant upon a very small fraction of its population—and that reality deserves serious consideration in any debate about future tax policy.