The United Kingdom is approaching a significant milestone, with tax receipts as a share of GDP expected to reach their highest level since the aftermath of the Second World War.
As Chancellor Rachel Reeves seeks to strengthen public finances through increased tax revenues, there are growing concerns among economists and professionals that higher effective tax rates may undermine incentives to work, particularly among the nation’s top earners.
This comes as many individuals face complex marginal tax rates and fiscal policies resulting in reduced take-home pay, raising questions about the broader impact on workforce participation and economic productivity.
Rising tax burden reaches record high
Official forecasts from the Office for Budget Responsibility (OBR) indicate that the total tax burden in the UK will reach 37.7% of GDP by the middle of next year.
This marks the highest level since available records began in 1948. The ratio has risen sharply from pre-pandemic levels, which stood at 32.9% in 2019. According to projections, this figure is set to climb further, reaching an estimated 38.5% at the start of the next decade.
The accelerated increase in the tax burden is attributed to a series of policy decisions, including the freezing of personal allowances and expansions in certain employer levies. These measures aim to address fiscal shortfalls but also introduce new challenges for taxpayers.
Impact on incentives for high earners
There is growing evidence that high marginal tax rates are affecting the behaviour and motivation of the UK’s top earners, often described as “high earners, not rich yet.
” Workers in sectors such as law, technology, consulting, and healthcare report that smaller net gains from pay increases are leading some to reconsider additional work or promotions.
According to Thomas Pugh, an economist at RSM UK, “there is evidence that punitive marginal tax rates are discouraging consultants in the public sector from taking on extra hours
” Polling indicates that a significant proportion of managers have acted to keep their incomes below certain tax thresholds to avoid steep marginal rates, with some reducing their hours or moving to part-time roles.
Historical context and OBR warnings
The OBR has expressed caution regarding the potential negative effects of rising tax rates on economic incentives. David Miles, a senior OBR official, stated that it is “very difficult to increase the tax take without having some negative effects on incentives somewhere in the system,”
Highlighting possible reductions in work, saving, investment, or hiring. Jagjit Chadha, Professor at the University of Cambridge, commented, “We are heading into very uncharted territory,” referencing the speed and scale of recent increases.
Economists suggest that tax policy changes since the late 2000s have contributed to such behavioural effects among high earners.
Marginal tax rate 'traps' and fiscal drag
The UK tax system includes several significant thresholds where taxpayers can experience very high marginal rates. A prominent example is the withdrawal of the personal allowance for incomes above £100,000, creating a marginal tax rate of 62% before considering factors such as student loan repayments.
Eligibility for certain childcare benefits is also lost once this threshold is crossed. Furthermore, the freezing of personal tax limits a process known as fiscal drag means millions of workers have been pulled into higher tax bands.
The Institute for Fiscal Studies (IFS) estimates that by 2028–2029, the number of people affected by the loss of personal allowances at the £100,000 threshold will reach 2.3 million, up by around half a million from the previous year.
Responses from economists and policymakers
Economists and tax policy analysts have highlighted the growing significance of these so-called “cliff-edges” in the tax system. Deven Ghelani of Policy in Practice notes that many professionals are seeking advice on how to manage their income to minimise the impact of these thresholds.
Both opposition and government politicians express concern. Dame Harriett Baldwin, a Conservative MP, said, “People respond to incentives and disincentives in the tax system, and the sooner our welfare and tax systems give clearer signals about the rewards of work and investment, the better.”
Final Summary
As the UK tax burden rises to historic levels, growing numbers of high earners face steep marginal rates and complex tax rules that may diminish the incentive to work more or pursue higher pay.
Economists and policymakers continue to debate the long-term impact, warning that both workforce participation and productivity could suffer if current trends persist. These developments prompt calls for careful tax policy review to ensure the rewards of extra effort and investment remain clear.
For individuals looking to better understand how tax policies affect their net pay, platforms like Pie offer useful tools to navigate the evolving landscape.
