For the current tax year, taxpayers with adjusted net income between £100,000 and £125,140 will face an effective marginal tax rate of 60%, as their £12,570 tax-free personal allowance is gradually withdrawn.

If a taxpayer earns over £100,000 in any tax year, their personal allowance is gradually reduced by £1 for every £2 of adjusted net income exceeding £100,000. This ceiling applies regardless of age, meaning that any taxable receipt that pushes their income above this threshold will lead to a reduction in their personal tax allowances. If their adjusted net income reaches £125,140 or more, the personal Income Tax allowance will be reduced to zero.

Adjusted net income refers to a taxpayer’s total taxable income before personal allowances, minus certain tax reliefs such as trading losses, charitable donations, and pension contributions.

Taxpayers in this income band should consider financial planning strategies to avoid this "personal allowance trap." Reducing income below £100,000 could be achieved by utilising options like increasing pension contributions, making charitable donations, or participating in certain investment schemes.

For higher-rate or additional-rate taxpayers seeking to reduce their tax bill, gifting to charity is one strategy. Donations made in the current tax year can be carried back to the 2024-25 tax year, provided the taxpayer requests the carry-back before or at the same time as submitting their self-assessment return, but no later than 31 January 2026.