Changing employment contracts: how employers should consult and seek agreement

Identify the contractual term before proposing a solution

Contractual terms are not limited to a signed document. GOV.UK explains that terms may appear in a written statement, offer letter, handbook or collective agreement; they can also be verbal, implied by law or established through custom and practice. Start by mapping where the relevant term comes from and who it covers.

Then define the business problem in neutral terms. If weekend demand has increased, the problem is not automatically “everyone must accept Saturday working”. Options might include volunteers, recruitment, a revised rota, overtime or a narrower contractual change. Acas advises employers to ask what they are trying to solve and whether a contract change is actually necessary.

Check linked risks before announcing the answer. A change to location, hours, pay or benefits may affect disabled employees, carers, parents, part-time workers or people with religious commitments differently. TUPE-protected terms, collectively agreed terms and pension changes can carry additional rules. Put the proposal on hold long enough to identify those routes.

Acas: considering changes to employees' contracts ↗ · GOV.UK: where contractual terms can be found ↗ · Related guide: TUPE checklist for employers →

A variation clause is not a blank cheque

Some contracts contain flexibility or variation clauses. Their wording and scope matter. A clause allowing a reasonable change to duties does not necessarily permit a substantial pay cut, permanent relocation or wholly different shift pattern. Acas warns that unilateral change can create breach-of-contract and constructive-dismissal risks, particularly where the wording is not clear and unambiguous.

Even where a clause appears relevant, act reasonably, give appropriate notice and consult about its effect. A manager should not discover the clause on Friday and tell an employee the new arrangement starts on Monday. Consider travel, childcare, health, cost and whether a phased or temporary arrangement could meet the business objective with less harm.

Do not assume silence equals agreement. Continued work can sometimes indicate implied acceptance, but an employee may be working under protest. Record questions and objections, and resolve whether agreement has actually been reached before changing payroll, hours or workplace systems.

Consult while the proposal can still change

Meaningful consultation is a discussion, not a notice that a decision has already been made. Give affected employees and any appropriate representatives the proposed wording, the business reason, who is affected, the intended timetable and the alternatives considered. Allow reasonable time for questions and counter-proposals.

For one employee, direct consultation may be proportionate. A wider change may need a recognised trade union, employee forum or elected representatives as well as individual discussion. Include people who are absent on sickness, maternity, paternity or adoption leave. If a recognised union negotiated the term, use the agreed collective bargaining route.

Keep a decision log: the information shared, meetings held, questions raised, alternatives tested and reasons for the final response. Consultation does not require agreement with every suggestion. It does require genuine consideration, a clear answer and evidence that the proposal was not treated as inevitable.

Acas: changes to employment contracts ↗ · Related guide: flexible working requests →

Confirm an agreed change precisely

Agreement should identify the exact term, start date and whether the change is permanent, temporary or subject to a trial. Record any protection, review point or transition arrangement. For example, a six-month location trial with mileage support is not the same agreement as an unrestricted permanent mobility clause.

The current statutory Code of Practice says it is good practice to communicate agreed changes in writing and give as much notice as reasonably practicable. Where the change affects particulars covered by the written statement of employment particulars, the employer must provide a written statement of the change within one month of the new term taking effect.

Update the documents that managers and payroll actually use. A signed letter is little help if the old rota, salary instruction or handbook remains live. Keep the employee's agreement and the final wording together, then check after implementation whether the arrangement is operating as intended.

GOV.UK: written statement of employment particulars ↗ · Related guide: written statement checklist →

If agreement is not reached, stop and reassess

Do not simply activate the new term. Unilateral imposition can lead to refusal to work, work under protest, unlawful-deduction or breach-of-contract claims, resignation and constructive-dismissal allegations, or discrimination claims. The correct risk depends on the term, the employee's status and service, and the reason and effect of the change.

Dismissal and re-engagement is not an ordinary implementation step. The statutory Code of Practice applies where an employer envisages dismissal if contractual changes are not agreed, regardless of the number affected, except where the only envisaged reason for dismissal is redundancy as legally defined. It requires ongoing good-faith consultation, genuine consideration of alternatives and use of dismissal and re-engagement only as a last resort.

The Code says an employer should contact Acas before raising that prospect. A tribunal must take relevant provisions into account, and can adjust compensation by up to 25% in specified claims where a party unreasonably fails to comply. Collective consultation, notice, fair-dismissal, equality and union rules may also apply. Pause for case-specific advice before making any threat or issuing notice.

GOV.UK: statutory Code on dismissal and re-engagement ↗

Contract change decision checklist

Legal requirements and official guidance were checked on 12 October 2026. This guide explains the current agreement-and-consultation route; a live dispute, TUPE change, union agreement or proposed dismissal needs advice on its specific facts.

• Define the operational problem and test whether a contractual change is necessary.
• Locate the term in the contract, written statement, policy, collective agreement or established practice.
• Identify everyone affected, including absent employees and any recognised union.
• Check equality, TUPE, pension, collective bargaining and health-and-safety implications.
• Write the proposed wording, business reason, timing and alternatives considered.
• Consult before the outcome is fixed and keep a record of counter-proposals.
• Use any flexibility clause only within its clear scope and in a reasonable way.
• Obtain clear agreement; do not treat silence or continued work as automatic consent.
• Confirm the final wording, effective date, duration, transition and review arrangements.
• Issue any required written statement of change within one month of the term taking effect.
• If agreement is not reached, pause before unilateral action or any dismissal proposal.