Flexitime: Definition & How It Works

Flexitime is a flexible working arrangement where employees choose their start and finish times around a set of core hours, rather than working a fixed schedule. It is one of the most common forms of flexible working in the UK, used by organisations ranging from SMEs to government departments. The model gives employees autonomy over their day while ensuring coverage during peak business hours.

If you are looking for a practical way to improve retention and attract talent without restructuring your workforce, flexitime is often the simplest place to start. This article explains how flexitime works, the key design choices, and how to implement it effectively.

Key Takeaways

• Flexitime lets employees choose their start and finish times within agreed parameters, with a fixed core hours period when everyone must be present.
• Core hours typically cover the middle of the working day (e.g. 10:00 to 15:00) to ensure team availability during peak periods.
• Compressed hours — working full weekly hours in fewer days — are a common flexitime variation.
• Flexitime improves retention, reduces absenteeism, and costs nothing to implement beyond a clear policy.
• You need a system to track flexi-balances to prevent hours drifting into overtime or excessive leave.

How Flexitime Works

The basic structure of a flexitime arrangement has three components:

1. Core hours — the period when all employees must be present. This is usually the middle of the day when meetings, collaboration, and customer-facing work happen most.
2. Flexi-band — the window outside core hours during which employees can choose their start and finish times. For example, if the flexi-band is 07:00 to 19:00 and core hours are 10:00 to 15:00, an employee can start at 07:00 and finish at 15:00, or start at 10:00 and finish at 18:00.
3. Flexi-balance — the running total of additional hours worked beyond the standard contract hours. Employees accumulate flexi-time credits for extra hours and build a debit if they work fewer hours.

Worked example:

• Contract: 37.5 hours per week (e.g. 7.5 hours x 5 days)
• Core hours: 10:00 to 15:00 (5 hours)
• Flexi-band: 07:00 to 19:00
• Monday: Employee starts at 07:30, finishes at 16:00 = 8.5 hours (+1.0 credit)
• Tuesday: Employee starts at 10:00, finishes at 17:00 = 7.0 hours (-0.5 debit)
• Wednesday: Employee starts at 08:00, finishes at 15:30 = 7.5 hours (neutral)
• End-of-week balance: +0.5 hours credit

Over time, accumulated credits can be taken as additional time off — typically half-days or full days once a threshold is reached.

Core Hours vs Flexi-Band Design

The design of your core hours and flexi-band determines how the system works in practice.

Design Choice	Recommendation
Core hours	4-6 hours in the middle of the day (e.g. 10:00 to 15:00)
Flexi-band	10-12 hours (e.g. 07:00 to 19:00)
Minimum flexi-credit threshold	Half-day at 3-4 hours; full day at 7-8 hours
Maximum flexi-debit	Cap at -7.5 hours (one full day)
Balance reset	Monthly or quarterly to prevent large build-ups
Overtime threshold	Any hours beyond the flexi-band count as overtime

Shorter core hours give employees more flexibility but reduce the window for team-wide meetings and collaboration. Longer core hours provide more structure but limit the benefit of flexitime.

Most organisations find that core hours of 10:00 to 15:00 strike the right balance — covering the busiest part of the day while allowing early starters and late starters to coexist.

Compressed Hours

Compressed hours are a popular variation of flexitime where employees work their full weekly hours in fewer days. For example:

• 9-day fortnight — work 75 hours over 9 days instead of 10, taking every other Friday off.
• 4-day week — work 37.5 hours across four 9.4-hour days, with a three-day weekend.
• 5/4 compressed — work 37.5 hours over 4.5 days, finishing at noon on Fridays.

Compressed hours are distinct from reduced hours — the employee works the same total hours, just in a different pattern. This matters for pay calculations, pension contributions, and statutory obligations.

Compressed hours are particularly popular in sectors where coverage is not essential five days a week — professional services, tech, and administrative roles. They are less suited to roles requiring daily customer-facing presence, though shift patterns can accommodate them.

Benefits of Flexitime

Flexitime is one of the lowest-cost, highest-impact workplace benefits available:

• Retention. Employees value flexibility more than many perks. CIPD research consistently finds that flexible working arrangements are among the top three reasons employees stay with an employer.
• Absenteeism. Employees with control over their schedules take fewer unplanned absences. They can manage appointments, childcare, and personal commitments without taking a full day off.
• Recruitment. Job adverts that mention flexitime attract significantly more applicants. In competitive hiring markets, flexibility is a differentiator.
• Productivity. Employees who work their most productive hours — rather than being tied to a rigid 9-to-5 — tend to produce better output.
• Wellbeing. Reduced commuting stress, better work-life balance, and the ability to manage personal responsibilities during the day all contribute to lower burnout rates.

Implementing Flexitime

Here is how to introduce flexitime in your workplace:

1. Set your parameters. Define the core hours, flexi-band, maximum credit/debit limits, and how balances are tracked.
2. Write a policy. Document the rules clearly — who is eligible, how flexi-balances work, what happens during holiday and sick leave, and how disputes are resolved.
3. Choose a tracking method. Use a spreadsheet, time-tracking software, or a leave management system that records daily hours and calculates balances automatically.
4. Communicate to the team. Explain the system, the expectations, and the policy. Make sure managers understand how to handle flexi-balance queries.
5. Set a review period. Run flexitime for 3-6 months, gather feedback, and adjust parameters as needed. What works in theory may need tweaking in practice.

Frequently Asked Questions

Is flexitime a legal requirement?

No. There is no UK law requiring employers to offer flexitime. It is a voluntary arrangement. However, since April 2024, all employees have the right to request flexible working from day one — and flexitime is a common form of flexible working that employers can offer in response to such requests.

Do employees accrue annual leave during flexitime?

Yes. Annual leave accrual is based on the employment relationship, not the number of hours worked in a given week. An employee on flexitime accrues statutory annual leave at the same rate as a fixed-schedule employee.

How do you handle flexitime for part-time employees?

Part-time employees can participate in flexitime by adjusting the core hours and flexi-band proportionally. For example, if a part-time employee works 20 hours per week across four days, their core hours might be 10:00 to 14:00 with a flexi-band of 08:00 to 17:00.

Can flexitime be withdrawn by the employer?

Yes, but you should follow a reasonable process. Flexitime is generally a non-contractual benefit unless explicitly stated in the employment contract. If business needs change, you can modify the system — but consulting with employees beforehand and explaining the reasons helps maintain trust and avoids grievances.

What happens to flexi-balances during holiday or sick leave?

Holiday and sick leave are paid at the employee’s normal rate and do not affect their flexi-balance. If an employee is on annual leave for a full week, they do not accumulate flexi-credits or build a debit for that week. The balance remains unchanged.