Can An Employer Change Working Hours In Great Britain?

Yes, you can change an employee's working hours in Great Britain, but usually not just by announcing the change and putting it on the next rota.

This article focuses on employers in England, Scotland and Wales. Northern Ireland has separate employment law, and some rules differ, including unfair dismissal qualifying periods. If your business employs staff in Northern Ireland, you should check the local position before relying on the process below.

The legal answer depends on what the employment contract says, how big the change is, whether the employee agrees, and how fairly you consult with them. If you get the process wrong, you could face breach of contract, unlawful deduction from wages, discrimination or unfair dismissal claims.

The good news is that this can be handled well with a clear business reason, a sensible consultation process and the right paperwork. Here's how to approach it in a way that protects your business and keeps the working relationship on track where possible.

Can You Change An Employee's Working Hours?

Yes, but in most cases you'll need either the employee's agreement or a clear contractual right to make the change.

Working hours are usually a core term of the employment contract. That might include:

• Start and finish times
• Days of work
• Total weekly hours
• Shift patterns or rota arrangements
• Whether overtime is required or optional
• Whether the employee works at night, weekends or public holidays

If the change is minor and the contract gives you flexibility, you may be able to make it after giving reasonable notice and consulting properly. For example, moving a shift start time from 9:00am to 9:30am may be easier to justify than moving someone from weekday day shifts to weekend night shifts.

If the change is significant, you should treat it as a variation of the employment contract. That usually means consulting with the employee, explaining the business reason, considering their feedback and recording any agreed change in writing.

If you impose a major change without agreement, the employee may continue working under protest and bring a claim, resign and claim constructive unfair dismissal if they have enough service, or refuse to work the new hours. None of those outcomes is ideal for a growing business.

What Does The Employment Contract Say About Changing Hours?

The contract is your starting point, because it tells you whether you already have some flexibility to change hours or shift patterns.

Look for clauses dealing with:

• Normal working hours: for example, 37.5 hours per week, Monday to Friday.
• Shift work: for example, hours set by rota and notified in advance.
• Flexibility: for example, a right to vary start times, finish times, days of work or location.
• Overtime: whether overtime is compulsory, voluntary or paid at a different rate.
• Notice of rotas: how much notice you need to give before changing a shift.

A flexibility clause can help, but it isn't a blank cheque. You still need to use it reasonably. If the clause says you can vary hours to meet business needs, that doesn't usually mean you can make sudden, extreme changes that seriously disrupt an employee's childcare, disability adjustments or caring responsibilities.

ACAS guidance encourages employers to consult with staff before changing employment contracts, even where the contract contains flexibility wording. A fair process reduces legal risk and often helps you find a practical compromise.

If your contracts are vague, outdated or silent on shift changes, don't assume you can fill the gaps later. This is where many disputes start. A tailored employment contract should reflect how your business actually operates, especially if your rosters change week to week.

How Should You Consult To Change Working Hours?

You should consult before making the change, unless the change is genuinely minor and already covered by the contract.

Consultation doesn't need to be complicated, but it should be real. That means giving employees enough information to understand what you're proposing and a genuine chance to respond before you make a final decision.

A Practical Consultation Process

1. Identify The Business Reason: Write down why the change is needed, such as customer demand, opening hours, cost pressures or health and safety cover.
2. Check The Contract: Review working hours, rota, flexibility and notice clauses before speaking to staff.
3. Prepare The Proposal: Set out the current hours, proposed hours, start date and expected impact on pay, breaks, overtime and holiday.
4. Meet With Affected Staff: Explain the proposal and invite questions, concerns and alternatives.
5. Consider Feedback Properly: Look at whether adjustments are possible, such as phasing the change or offering different shift options.
6. Confirm The Outcome In Writing: Record what has been agreed or, if agreement isn't reached, set out the next steps.

The length of consultation depends on the circumstances. A small rota adjustment might only need a short discussion. A major change across a team may need several meetings and written updates.

If you're proposing to dismiss and re-engage 20 or more employees at one establishment within 90 days or less, collective consultation rules may apply. The minimum consultation period is 30 days before the first dismissal, or 45 days if 100 or more dismissals are proposed. You should get negotiation support early if you're anywhere near that point.

Can You Change Shift Patterns Without Agreement?

Sometimes, but only where the contract allows it and you act reasonably. If the contract doesn't allow it, you should aim to get agreement first.

Shift changes are common in hospitality, retail, cleaning, care, logistics and customer support. The risk is that a shift pattern often affects more than the hours on paper. It can affect childcare, transport, caring responsibilities, health conditions, religious observance and second jobs.

Say Priya runs a cafe in Manchester. Her cafe opens from 7:00am to 3:00pm, Monday to Friday. Demand picks up on weekends, so she wants two staff members to move from Monday to Friday shifts to Wednesday to Sunday shifts.

One employee's contract says their hours are 8:00am to 4:00pm, Monday to Friday. Another employee's contract says they work 35 hours per week over any five days, with shifts notified at least two weeks in advance.

Priya has more flexibility with the second employee, but she should still consult, give proper notice and consider any concerns. For the first employee, moving them to weekends is a more significant contract change. Priya should seek agreement and record the employment contract variation in writing before changing the rota.

Even where a change looks operationally sensible, don't overlook the Working Time Regulations 1998. You need to factor in rest breaks, daily rest, weekly rest, the 48-hour average weekly working limit unless there's a valid opt-out, and special rules for night workers.

What Are The Main Legal Risks When Changing Hours?

The main risks are breach of contract, unfair dismissal, unlawful deduction from wages and discrimination.

A breach of contract risk comes up where you change agreed hours without a contractual right or the employee's agreement. If the change affects pay, you may also face an unlawful deduction from wages claim under the Employment Rights Act 1996.

Unfair dismissal risk can arise if an employee resigns because the change is serious enough to destroy trust and confidence, or if you dismiss and re-engage them on new terms. For dismissals in England, Scotland and Wales with an effective date of termination before 1 January 2027, employees usually need two years' continuous service to claim ordinary unfair dismissal. From 1 January 2027, this reduces to six months. Northern Ireland has separate rules, where the ordinary qualifying period is usually one year. Some claims don't require the ordinary qualifying period, such as discrimination claims and automatically unfair dismissal claims, including certain whistleblowing related claims.

Discrimination risk is easy to miss. A change that applies to everyone can still disadvantage certain groups. For example:

• A move to late shifts may disadvantage employees with childcare responsibilities, which can raise sex discrimination risks.
• A rota change may affect an employee with a disability who needs a consistent routine or medical appointments.
• Weekend working may conflict with religious observance.
• Short notice changes may disadvantage employees who rely on fixed transport or care arrangements.

The Equality Act 2010 can apply even if you didn't intend to discriminate. The safer approach is to ask about individual impacts, consider reasonable adjustments where disability is involved, and keep notes showing how you weighed up the business need against staff concerns.

You should also be careful with flexible working requests. Since 6 April 2024, eligible employees can make a statutory flexible working request from day one of employment and can make two requests in any 12-month period. You still have business grounds to refuse in appropriate cases, but you need to follow the statutory process and respond within two months unless agreed otherwise.

Do You Need A New Contract Or A Variation Letter?

You need written evidence of the change, but whether that's a new contract or a variation letter depends on how much is changing.

If you're only changing one or two terms, a contract variation letter is usually enough. If you're changing several key terms, or your current contracts are old and don't match how the business operates, a new employment contract may be cleaner.

What To Include In A Working Hours Variation Letter

A variation letter should be tailored before you use it. Templates can be a helpful starting point, but they often miss the details that matter for your industry, rosters, employment contract terms and pay arrangements.

1. Employee And Employer Details: Name the employee, your business and the original contract date.
2. Current Working Hours: State the existing hours or shift pattern being changed.
3. New Working Hours: Set out the new days, start and finish times, weekly hours or rota rules.
4. Start Date: Give the date the new arrangement begins and whether there's a trial period.
5. Pay And Benefits: Confirm any effect on salary, hourly pay, overtime, allowances, holiday pay or benefits.
6. Breaks And Working Time: Confirm the arrangement will comply with rest breaks, rest periods and working time limits.
7. Reason For The Change: Briefly explain the business reason, such as opening hours or customer demand.
8. Agreement Wording: Ask the employee to sign and date the letter to confirm agreement.
9. Terms That Stay The Same: Say that all other contract terms continue unless varied by the letter.

Under section 4 of the Employment Rights Act 1996, you must give employees a written statement of changes to certain employment particulars at the earliest opportunity and no later than one month after the change. In practice, it's better to get the signed variation before the change starts.

What If An Employee Refuses The New Hours?

If an employee refuses, don't jump straight to dismissal. First, slow down, document the issue and see whether agreement is still possible.

Start by asking why they can't agree. Their reason may reveal a legal risk or a workable compromise. For example, you might be able to offer a phased start date, a different shift, a trial period, or a temporary arrangement while they sort out childcare.

Keep records of:

• The business reason for the proposed change
• The contract clauses you relied on
• Meeting notes and correspondence
• Alternatives suggested by you or the employee
• Any equality, health, safety or working time issues raised
• The final decision and why you reached it

If agreement still isn't possible, your options may include keeping the existing hours, making a different operational change, or dismissing and offering re-engagement on new terms. Dismissal and re-engagement is sometimes called fire and rehire, and it should be treated as a last resort.

The statutory Code of Practice on Dismissal and Re-engagement has applied since 18 July 2024. Employment tribunals can apply an uplift of up to 25% to certain awards if you unreasonably fail to follow it. The Code focuses on meaningful consultation, avoiding threats of dismissal too early, and exploring alternatives.

If dismissal becomes a genuine possibility, check notice rights carefully. Statutory minimum notice is one week after one month's service, then one week for each complete year of service from two years up to a maximum of 12 weeks. The contract may give more notice, and you need to follow a fair process.

Key Takeaways

• In England, Scotland and Wales, you can change working hours, but you usually need agreement or a clear contractual right to do so.
• Northern Ireland has separate employment law, so check the local position if you employ staff there.
• A flexibility clause helps, but you still need to consult and use it reasonably.
• Major changes to hours, days or shift patterns should be recorded in a signed variation letter or new contract.
• Check Working Time Regulations, pay, holiday, discrimination risks, flexible working rights and unfair dismissal qualifying periods before confirming the change.
• If an employee refuses, keep careful records and explore alternatives before considering dismissal and re-engagement.

If you'd like help with reviewing your employment contracts, consulting on changes to working hours, preparing variation letters or managing a refusal to agree new shifts, you can reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.