How to Calculate Overtime in the UK: Rates, Rules & Examples (2026)

Overtime is a fact of life for most UK businesses. Whether it is a seasonal rush, a major project deadline, or simply covering for an absent colleague, there will be weeks when your team works beyond their contracted hours. The question every employer and employee needs to answer is: how should those extra hours be paid?

Unlike many other countries, UK law does not require employers to pay a premium rate for overtime. There is no statutory right to time-and-a-half or double time. Instead, overtime pay is governed by what is written in the employment contract. That said, most employers do offer enhanced rates — both because it is fair and because it helps attract and retain staff.

This guide explains exactly how overtime works in the UK, walks through the most common pay rates, and provides step-by-step worked examples you can apply to your own payroll. We also cover the legal limits on working hours, how overtime interacts with the Working Time Regulations, and the often-overlooked link between overtime and the National Minimum Wage.

"Overtime disputes are one of the most common causes of payroll queries. Getting the calculations right — and documenting them clearly — saves hours of back-and-forth every pay period."

Is Overtime Pay a Legal Requirement in the UK?

The short answer is no — there is no UK law that forces employers to pay extra for overtime hours. The key legal points are:

• No statutory overtime premium. The Employment Rights Act 1996 and the Working Time Regulations 1998 set out rules about maximum hours and rest breaks, but neither mandates a specific overtime rate.
• The contract is king. Whatever your employment contract (or staff handbook) says about overtime pay is what applies. If the contract says overtime is paid at the basic rate, that is the rate. If it says time-and-a-half, that is the rate. If the contract is silent on overtime pay, the employer is not obliged to pay anything above the basic hourly rate for extra hours — provided the effective hourly rate does not fall below the National Minimum Wage.
• Employers cannot force unpaid overtime that breaches NMW. Even where the contract states overtime is unpaid, the total pay divided by total hours worked must not fall below the National Minimum Wage. This is a legal requirement under the National Minimum Wage Act 1998.
• Collective agreements may apply. In unionised workplaces, overtime rates are often negotiated as part of a collective bargaining agreement and are binding on both parties.
• Custom and practice. If your organisation has consistently paid overtime at a particular rate for years, employees may argue it has become an implied contractual term — even if the written contract does not mention it.

In practice, the vast majority of UK employers offer some form of overtime premium. A 2025 CIPD survey found that over 70% of organisations paying overtime used either time-and-a-half or a fixed overtime rate above the basic hourly pay. Offering competitive overtime rates is also essential for recruitment in sectors like construction, healthcare, and logistics.

Common UK Overtime Rates

While there is no legal standard, three overtime rates dominate across UK industries. The table below summarises each rate and when it is typically applied:

Some employers also use 1.25x (time-and-a-quarter) for the first few hours of weekday overtime, stepping up to 1.5x thereafter. Others offer a flat overtime allowance rather than an hourly multiplier. Whatever structure you use, it should be clearly documented in the employment contract or company policy.

For guidance on how to structure and communicate your overtime policy, see our UK timesheet management guide.

How to Calculate Overtime Pay (Step by Step)

The basic overtime calculation follows this formula:

Let us work through three realistic examples.

Example 1: Standard Overtime at Time-and-a-Half

Example 2: Mixed Rate Overtime (1.5x Then 2x)

Stop Manual Overtime Calculations

Automatic time-and-a-half and double-time calculations. Works for hourly, salaried, and mixed-rate employees.

Start Free Trial

Example 3: Salaried Employee with Overtime

These three examples cover the vast majority of overtime scenarios. The key takeaway: always start by identifying the basic hourly rate, then multiply by the overtime multiplier for each band. If you manage a team, a good timesheet management system will do these calculations automatically.

The 48-Hour Working Week Limit

Before authorising overtime, every UK employer must understand the Working Time Regulations 1998 (WTR). The headline rule is:

Workers must not work more than an average of 48 hours per week, calculated over a 17-week reference period.

This includes overtime. If an employee's contracted hours are 40 per week and they regularly work 10 hours of overtime, they are averaging 50 hours — which breaches the WTR unless they have opted out. Key points:

• The 17-week rolling average. It is the average over 17 weeks that matters, not any single week. An employee can work 55 hours in one week without breaching the regulations, provided their average across the reference period stays at or below 48.
• Opt-out agreements. Workers can voluntarily opt out of the 48-hour limit by signing a written agreement. The opt-out must be genuinely voluntary — you cannot make it a condition of employment. Workers can cancel an opt-out at any time, typically with 7 days' notice (or up to 3 months if specified in the agreement).
• Young workers (under 18). The rules are stricter. Workers under 18 cannot work more than 8 hours per day or 40 hours per week, with no opt-out available.
• Night workers. Night workers must not average more than 8 hours per 24-hour period. If their work involves special hazards or heavy physical/mental strain, the 8-hour limit applies to every single shift, not just the average.
• Record-keeping. Employers must keep records of working hours for at least 2 years to demonstrate compliance. This is where proper time tracking becomes essential. Without records, you cannot prove compliance if challenged by an employee or inspector.

The Health and Safety Executive (HSE) enforces the WTR and can issue improvement notices or prosecute employers who fail to comply. Penalties for breaches are unlimited — though in practice, most enforcement action begins with a warning. For a comprehensive overview of all the regulations, see our Working Time Regulations UK guide.

Overtime and National Minimum Wage

This is the area where many employers unintentionally break the law. Even if you pay the correct overtime rate, the National Minimum Wage Act 1998 requires that a worker's average hourly pay — across all hours worked — must not fall below the NMW/NLW.

The current rates (from April 2025) are:

How Overtime Can Push You Below NMW

The most common scenario involves salaried workers who do unpaid overtime. Here is how it works:

How to Check Compliance

HMRC assesses NMW compliance by looking at the pay reference period(usually a week or month, matching your pay cycle). The calculation is:

If the result is below the NMW, you have a compliance issue — regardless of what the contract says about overtime being "unpaid" or "included in salary." HMRC can fine employers up to 200% of the underpayment (capped at £20,000 per worker) and publicly name offending businesses.

The best protection is to track all hours worked — including unpaid overtime — and run the NMW check every pay period. See our guide to HMRC timesheet requirements for the full record-keeping obligations.

TOIL (Time Off in Lieu)

Not every organisation pays overtime in cash. A common alternative is Time Off in Lieu (TOIL), where employees "bank" their overtime hours and take them as paid time off later. TOIL is particularly popular in the public sector, charities, and professional services firms.

How TOIL Works

• Hour-for-hour: The simplest approach. One hour of overtime earns one hour of TOIL. If an employee works 3 extra hours on Tuesday, they take 3 hours off later in the week or month.
• Enhanced TOIL: Some employers apply the overtime multiplier to TOIL as well. For example, 3 hours of overtime at time-and-a-half would earn 4.5 hours of time off.
• Capped TOIL: To prevent excessive TOIL balances, many employers set a maximum accrual (e.g., 2 days per month) and require TOIL to be used within a set timeframe (e.g., within 3 months).

Legal Considerations for TOIL

• TOIL must be agreed, not imposed. If the employment contract specifies overtime will be paid, the employer cannot unilaterally switch to TOIL without the employee's agreement.
• TOIL arrangements should still comply with the NMW. If an employee is never able to take their TOIL (because the workplace is too busy), they have effectively worked unpaid hours — which could push their effective rate below the minimum wage.
• When an employee leaves, any outstanding TOIL balance should be either paid out or taken during the notice period. Check your TOIL policy to ensure it covers this.
• TOIL does not exempt employers from the 48-hour weekly limit. The hours are still worked, even if the compensation comes as time off rather than pay.

For more on how TOIL interacts with holiday entitlement, see our guide to calculating holiday entitlement in the UK.

Recording Overtime Hours

Accurate overtime records are not just good practice — they are a legal necessity. Under the Working Time Regulations 1998, employers must maintain records sufficient to show compliance with the 48-hour limit. Under the National Minimum Wage Act, you need records to prove that every worker's effective hourly rate meets the NMW.

What to Record

• Employee name and identifier
• Date of the overtime
• Start time and end time (or total overtime hours)
• The overtime rate that applies (1x, 1.5x, 2x, TOIL, etc.)
• Manager approval (who authorised the overtime and when)
• Whether the overtime was pre-approved or claimed retrospectively

Best Practices

• Require pre-approval. A clear overtime authorisation process prevents disputes. Employees should request overtime in advance, with a manager approving or declining before the hours are worked — except in genuine emergencies.
• Use digital timesheets. Paper timesheets are error-prone and easy to lose. Digital timesheet software creates an automatic audit trail and makes payroll export straightforward.
• Integrate with payroll. The fewer manual steps between a timesheet and a payslip, the fewer errors. Look for software that exports overtime data directly to your payroll provider.
• Retain records for 6 years. While the WTR minimum is 2 years, HMRC can investigate NMW compliance going back 6 years. Keeping records for the longer period protects you in the event of an audit.

TimeTally makes overtime recording effortless. Employees log their hours from any device, managers approve with one click, and overtime is automatically categorised by rate band and exported to payroll. No spreadsheets, no manual calculations, no compliance gaps.

Automate Your Overtime Tracking

Automatic overtime calculations, 48-hour breach alerts, and seamless payroll export. No more manual tracking errors.

Start Free Trial

Overtime for Different Worker Types

Overtime rules and calculations can vary depending on the type of worker. Here is a quick overview:

Full-Time Employees

The most straightforward scenario. Overtime is typically any hours worked above the contracted weekly hours (usually 35, 37.5, or 40). The overtime rate and process should be stated in the employment contract.

Part-Time Employees

Part-time workers are entitled to the same overtime rate as comparable full-time colleagues, under the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000. However, a common question is: when does overtime "start" for a part-timer?

Many employers only pay the overtime premium once the part-timer exceeds the full-time threshold. For example, if a part-timer works 20 hours per week and the full-time contract is 37.5 hours, overtime at 1.5x might only apply after 37.5 hours — with hours between 20 and 37.5 paid at the basic rate. Check your contracts carefully, as this is an area where inconsistency leads to grievances.

Agency Workers

Agency workers are covered by the Working Time Regulations from day one. After 12 weeks in the same role, the Agency Workers Regulations 2010 entitle them to the same basic terms as permanent staff — which may include overtime rates if permanent employees in comparable roles receive them.

Zero-Hours Contract Workers

Workers on zero-hours contracts do not have "contracted hours," so the concept of overtime is blurred. Typically, any premium rate would be specified in the contract and triggered after a specific number of hours per week. The NMW check is particularly important for these workers — see our guide to tracking employee hours legally.

Tax and Pension Implications of Overtime

Overtime pay is treated as normal earnings for tax and National Insurance purposes. There is no special tax treatment. This means:

• Income Tax: Overtime pay is added to basic pay and taxed at the employee's marginal rate through PAYE. A large amount of overtime in one month could temporarily push an employee into a higher tax band.
• National Insurance: Both employer and employee NICs apply to overtime pay in the same way as basic pay.
• Pension auto-enrolment: Overtime pay counts towards qualifying earnings for auto-enrolment pension contributions. If an employee's overtime pushes their total earnings above the qualifying earnings threshold (£6,240 in 2025/26), pension contributions must be calculated on the overtime as well. This can increase both employer and employee pension costs.
• Holiday pay: Following the landmark Bear Scotland v Fulton (2015) ruling, regular overtime must be included in holiday pay calculations. If an employee regularly works overtime, their holiday pay should reflect their normal remuneration — not just the basic contracted pay. This applies to the first 4 weeks of statutory leave (the EU-derived entitlement). The additional 1.6 weeks can be paid at basic rate.

These implications make it all the more important to keep accurate overtime records. For a deeper look at what HMRC expects, read our HMRC timesheet requirements guide.

Frequently Asked Questions

Can my employer force me to work overtime?

Only if your contract includes an overtime clause that requires you to work extra hours when asked. Even then, the employer must comply with the 48-hour limit (unless you have opted out) and all rest break requirements. Refusing overtime that is not contractually required cannot be used as grounds for disciplinary action.

Is overtime pay mandatory in the UK?

No. There is no UK law requiring employers to pay a premium for overtime. However, the total pay for all hours worked must not fall below the National Minimum Wage. Overtime rates are determined by the employment contract, not by statute.

Do I have to pay overtime on bank holidays?

Not unless the employment contract or collective agreement says so. There is no automatic right to enhanced pay on bank holidays in the UK. Many employers choose to pay double time on bank holidays as a goodwill gesture, but this is contractual, not statutory. For more on bank holiday entitlements, see our holiday entitlement guide.

How is overtime calculated for night shifts?

Night shift overtime follows the same formula as daytime overtime — hours beyond the contracted amount, multiplied by the applicable rate. However, night workers have additional protections under the WTR: they must not average more than 8 hours per 24-hour period, and employers must offer free health assessments.

Can salaried employees claim overtime?

It depends entirely on the contract. Many salaried roles state that "reasonable overtime" is included in the salary. Others explicitly offer overtime at 1x, 1.5x, or TOIL. If the contract is silent, the employee has limited recourse — but the NMW check still applies.

Summary: Key Takeaways

• UK law does not mandate overtime premiums — overtime pay is governed by the employment contract, not statute.
• The most common rates are 1x (standard), 1.5x (time-and-a-half), and 2x (double time).
• Always check that total pay ÷ total hours ≥ National Minimum Wage, especially for salaried workers doing unpaid overtime.
• The 48-hour weekly limit (averaged over 17 weeks) applies to all hours including overtime, unless the worker has opted out.
• TOIL is a valid alternative to overtime pay, but must be agreed and properly managed.
• Record all overtime — for WTR compliance, NMW compliance, and correct payroll processing.
• Overtime affects tax, NICs, pension contributions, and holiday pay.

Getting overtime right protects your business legally and keeps your employees fairly compensated. Whether you calculate overtime manually or use software like TimeTally to automate the process, the principles in this guide will ensure your calculations are accurate, compliant, and transparent.

Get Overtime Right Every Time

Automatic rate calculations, NMW compliance checks, and Working Time Regulations monitoring. Protect your business and pay your team fairly.

Start Free Trial