How is a retention bonus taxed in the UK?

Full answer

A retention bonus (sometimes called a "stay bonus") is a lump sum an employer pays to encourage a valued employee to remain in their role for a defined period, commonly used during company acquisitions, major restructurings, critical projects, or when a key member of staff has been headhunted elsewhere. **Tax treatment** HMRC treats a retention bonus as ordinary employment earnings, taxed in exactly the same way as a normal salary payment or discretionary bonus. It is added to your gross pay in the period it is paid and subject to Income Tax at your marginal rate (20% basic, 40% higher, 45% additional for 2026/27) and Class 1 employee National Insurance (8% between the primary threshold of £12,570 and the upper earnings limit of £50,270, then 2% above), deducted through PAYE by your employer. **Effect on your pay for that month** Because a retention bonus is often a large one-off lump sum, it can push your income for that particular pay period into a higher tax band, even if your annual salary would not normally reach it, since PAYE calculates tax on each pay period as if that level of pay continued all year. This is why a retention bonus can appear to be "taxed very heavily" on the payslip in the month it is paid; any resulting overpayment for the year as a whole is usually corrected automatically by the end of the tax year, or can be reclaimed sooner if needed. **Contractual conditions and clawback** Retention bonuses are typically conditional on the employee remaining employed until a specified date (for example, twelve months after a company acquisition). If the employee leaves before that date, many retention bonus agreements include a clawback clause requiring some or all of the after-tax amount to be repaid. Because Income Tax and National Insurance were already deducted and paid over to HMRC at the time the bonus was originally paid, repaying a clawed-back bonus does not automatically reverse that tax; instead there are specific HMRC-approved mechanisms (adjusting a later payslip, or in some cases claiming relief through Self Assessment) to correct the tax position, and the exact approach depends on whether the repayment happens in the same tax year or a later one. **Reducing the tax impact through pension sacrifice** Some employees choose to sacrifice all or part of a retention bonus into their workplace pension via salary sacrifice, before it is paid as cash. Because pension contributions made this way are not treated as taxable pay, this avoids Income Tax and National Insurance on the sacrificed amount entirely (subject to the pension Annual Allowance, £60,000 for most people in 2026/27), which can be attractive for higher and additional-rate taxpayers who do not urgently need the cash. **Worked example** An employee due a £15,000 retention bonus after a company merger, already earning £45,000 a year, would see the bonus pushed into a mix of basic and higher-rate tax in the month it is paid, since £15,000 added to that month's equivalent salary crosses the £50,270 higher-rate threshold. After 40% Income Tax and 2% NI on the portion above the threshold, and 20% Income Tax and 8% NI on the portion below, the employee keeps considerably less than £15,000 in hand -- illustrating why some employees negotiate to have part of a large bonus paid into a pension instead.

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