What is the 60% Tax Trap? UK Tax Guide & Thresholds for 2026/27

When advising high-earning individuals in the UK, one of the most punitive marginal tax rates arises not from a statutory tax band, but from the withdrawal of a fundamental allowance. If your clients ask “what is the 60% tax trap?”, you must guide them through the statutory mechanics of the Personal Allowance taper and the specific definition of “Adjusted Net Income” (ANI).

For the 2026/27 tax year, the government has frozen the standard thresholds, meaning more taxpayers will inadvertently cross into this bracket through standard salary inflation.

The Statutory Mechanics of the 60% Trap

The 60% tax trap is an effective marginal rate of income tax that hits taxpayers earning between £100,000 and £125,140.

Primary legislation creates this trap via section 35 of the Income Tax Act 2007 (ITA 2007). Section 35(1) grants an individual a standard Personal Allowance, which is frozen at £12,570 for the 2026/27 tax year.  However, section 35(2) mandates a harsh withdrawal: for any individual whose adjusted net income exceeds £100,000, the allowance is reduced by one-half of the excess.

Because the higher rate of income tax for 2026/27 is 40%, this £1-for-£2 withdrawal creates an effective 60% tax rate on income within the band.

The Arithmetic of the Trap

To demonstrate how this costs the taxpayer:

1. A taxpayer earns an extra £100 above the £100,000 threshold.
2. They pay the standard 40% higher rate tax on that £100, costing £40.
3. Simultaneously, section 35(2) ITA 2007 reduces their tax-free Personal Allowance by £50 (half the excess).
4. That lost £50 of allowance is now suddenly taxable at the 40% higher rate, creating an additional £20 tax charge.
5. Total tax on the £100 of income = £40 + £20 = £60 (an effective 60% rate).

Once a taxpayer reaches £125,140, they have fully lost their £12,570 Personal Allowance.  Any income above this exact figure then falls into the Additional Rate band, which taxes income at a lower statutory rate of 45%.  Finance Act 2026 confirms that the Personal Allowance remains frozen at £12,570 until the 2030-31 tax year, ensuring this £125,140 threshold remains static.

The Trigger: Adjusted Net Income (ANI)

The £100,000 threshold does not apply to gross salary alone; it applies to “Adjusted Net Income”. You must calculate this figure strictly according to the statutory steps in section 58 ITA 2007.

Under section 58(1), you calculate ANI using the following steps:

• Step 1: Take the individual’s total net income for the tax year.
• Step 2: Deduct the grossed-up amount of any qualifying Gift Aid donations made in the year.
• Step 3: Deduct the gross amount of any pension contributions paid under relief at source arrangements.
• Step 4: Add back certain specific reliefs (such as payments to trade unions).

Because Steps 2 and 3 reduce the final ANI figure, taxpayers can actively use these deductions to pull their income below the £100,000 threshold and reclaim their Personal Allowance.

Compounding the Issue: The HICBC Trap

When reviewing a client’s marginal rates, you must also consider the High Income Child Benefit Charge (HICBC), which creates a separate but similar trap for families earning slightly less.

For the 2026/27 tax year, the HICBC threshold sits at £60,000.  For every £200 of adjusted net income a taxpayer earns above £60,000, the government levies a tax charge equal to 1% of their Child Benefit entitlement, culminating in a full 100% clawback at £80,000.  This creates punitive marginal tax rates for families in the £60,000 to £80,000 bracket before they even reach the 60% trap at £100,000.

Mitigation Strategies for the 2026/27 Tax Year

To protect clients from the 60% tax trap, advisors should model the following mitigation strategies:

1. Relief at Source Pension Contributions

If a client expects an ANI of £110,000, they face a £6,000 tax bill on the top £10,000 of income. Under section 58 Step 3, they can make a gross pension contribution of £10,000 (net cash cost of £8,000).  This pulls their ANI exactly down to £100,000, restoring £5,000 of their Personal Allowance and delivering total tax relief of 60% on the contribution.

2. Gift Aid Donations

Under section 58 Step 2, charitable donations made via Gift Aid also reduce ANI.  If a client donates £8,000 to charity, the grossed-up amount (£10,000) deducts from their ANI, restoring their Personal Allowance while supporting the charity.

3. Salary Sacrifice

Implementing a salary sacrifice arrangement for employer pension contributions is highly effective. Because the employee contractually gives up the right to the salary before they earn it, the foregone amount never forms part of their gross income. Therefore, it completely bypasses the section 58 ANI calculation at Step 1, while additionally saving on National Insurance contributions.

Summary of 2026/27 Thresholds and Outcomes

Next steps for advisors: Calculate your clients’ projected Adjusted Net Income well before the 5 April 2027 year-end, and advise on optimal gross pension contributions or salary sacrifice arrangements to drag their ANI back down to £100,000.