Designing a bonus scheme in the United Kingdom
Reviewed by Mellow Editorial Team, HR & payroll content team
Bonuses are entirely discretionary unless a contract or policy says otherwise — but once you promise one, it becomes a legal obligation. That distinction shapes every design decision you make.
Discretionary versus contractual bonuses
Before you write a single target, decide which type of bonus you are creating.
A discretionary bonus gives you the right to award, adjust or withhold a payment based on business circumstances. You can consider company performance, individual behaviour, or simply whether the business can afford it. The key is that the contract must genuinely reserve that discretion — vague wording that implies a bonus is expected can make it contractual in practice, regardless of what you intended.
A contractual bonus is a binding obligation. If an employee meets the stated criteria, they are entitled to the payment. Fail to pay it and you face a breach of contract claim. This structure suits roles where the link between effort and outcome is clear and measurable, such as sales.
Most schemes sit somewhere between the two: a formulaic target element (contractual) combined with a modifier for company performance or conduct (discretionary). Whatever you design, make the mechanics explicit in writing.
Choosing a bonus structure
Common structures used by UK employers include:
Individual performance bonus. Tied to objectives set at the start of the year. Works well where individual contribution is measurable. Requires a robust appraisal process — if your line managers do not have consistent conversations, the scheme will feel arbitrary.
Profit share. A percentage of company profit distributed to employees, often based on salary or tenure. Builds collective ownership of results. The downside is that employees may feel disconnected from a number they cannot influence directly.
Sales commission. A percentage of revenue or margin generated. The most directly motivating structure for commercial roles, but it needs careful design to avoid incentivising the wrong behaviours — discounting too heavily, for example, or cherry-picking easy deals.
Spot or recognition bonuses. One-off payments for specific contributions. Useful for rewarding behaviour you want to see repeated. Low admin overhead, but use them consistently or you create a perception of favouritism.
You can combine structures. A common approach is a base bonus pool set by company performance, allocated to individuals based on personal performance ratings.
Setting targets that are fair and measurable
Poorly written targets are the most common reason bonus schemes fail. Employees stop engaging when they feel targets are moving, inconsistent, or impossible to hit.
Practical guidelines:
- Write targets at the start of the performance period, not retrospectively.
- Make them specific enough that a reasonable person could assess whether they were met.
- Distinguish between threshold (minimum to earn anything), target (expected outcome) and stretch (maximum payout).
- Document how you will handle edge cases: someone who joins mid-year, goes on maternity leave, or is under a performance improvement plan.
The Employment Rights Act 2025 has strengthened day-one rights, which increases the importance of documenting how part-year employees are treated in your bonus policy. A new joiner in month ten should know from day one what, if anything, they can expect.
Tax and payroll treatment
Bonuses are earnings for PAYE purposes. They attract income tax and National Insurance in the same way as regular salary, processed through payroll in the pay period they are paid.
For employees, income tax applies at 20% on earnings within the basic-rate band, 40% at the higher rate and 45% above the additional rate threshold, after the personal allowance of £12,570. Employee National Insurance runs at 8% (and 2% above the upper earnings limit). Employer National Insurance on bonuses is 13.8%.
A large bonus paid in a single month can push an employee into a higher tax band for that pay period even if their annual earnings do not justify it. This is a feature of the PAYE system, not an error — but employees sometimes find it confusing. It is worth setting expectations in advance.
Bonuses must be reported to HMRC under Real Time Information via a Full Payment Submission on or before the payment date. If you pay bonuses outside your normal payroll cycle, make sure your payroll software or provider is briefed in advance. Pension auto-enrolment contributions may also apply depending on whether the bonus forms part of qualifying earnings under your scheme.
Communicating the scheme
A well-designed scheme that employees do not understand is worthless. Communication is part of the design, not an afterthought.
At minimum, employees should receive a written summary covering: how the bonus is calculated, when it is paid, what happens if they leave before the payment date, and how discretion is applied. Be honest about the discretionary elements rather than implying certainty you cannot guarantee.
Review the scheme annually. Business priorities change, and a target that made sense in 2025/26 may be meaningless in 2026/27. A quick annual reset keeps the scheme credible and motivating rather than something people have quietly stopped believing in.
---
Run HR and payroll in United Kingdom with Mellow
Mellow brings HR, payroll and 12 AI agents into one platform — built to handle United Kingdom properly, with payroll included, from £4 per employee per month. The AI agents don't just answer questions; they generate contracts, run cost estimates and draft letters for you.
- United Kingdom payroll software
[Start a free trial →](/register)