The key changes employers need to prepare for
The Employment Rights Act 2025 introduces the most significant expansion of employee rights in a generation. For most employers the headline change is the cut in the qualifying period for ordinary unfair dismissal from two years to six months, for dismissals with an effective date of termination on or after 1 January 2027, when the cap on the compensatory award is also removed. The original plan for day-one unfair dismissal rights was dropped. Some changes are already in force: since 6 April 2026 Statutory Sick Pay has been payable from the first day of sickness, with no lower earnings limit.
Other changes in the Act include: employers having to show that refusing a flexible working request is reasonable; zero-hours and low-hours workers gaining a right to be offered guaranteed hours that reflect the hours they regularly work; stronger duties to prevent sexual harassment, including by third parties; and wider trade union access rights. Several of these depend on regulations and commencement dates that are still being finalised.
Not all reforms have confirmed implementation dates. Leadership teams should separate confirmed commencement orders from proposals still in consultation. Planning against unconfirmed assumptions creates effort that may need to be re-done when dates slip.
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The six-month unfair dismissal rule: practical implications
Once the six-month qualifying period applies, an employee with six months' continuous service can bring an ordinary unfair dismissal claim, so a dismissal after that point needs a fair reason and a fair process. Protection that already applies from day one, such as dismissal for pregnancy or whistleblowing, is unchanged. Probation reviews therefore need to happen, and be documented, well inside the first six months, allowing for the notice period.
In practice, this means probation management needs to become more structured. Clear performance objectives at the start of employment, documented mid-probation reviews, and formal probation failure conversations with evidence all become more important. The risk of an informal 'this isn't working' conversation followed by immediate dismissal is materially higher than under the current two-year qualifying period.
Review your probation policy and manager training before implementation. Line managers are often the weakest link in probation management because they are not trained to give honest performance feedback early enough for it to be documented and acted on within the probation window.
Flexible working and zero-hours changes
Flexible working is already a day-one right to request since April 2024, but the Employment Rights Act extends this by limiting the grounds on which employers can refuse. Where flexible working is refused, the reasons must be demonstrably reasonable and documented. This raises the bar above the current eight statutory grounds for refusal.
Zero-hours and minimum-hours workers who work a regular pattern over a reference period will be entitled to a guaranteed-hours contract reflecting that pattern. Employers who rely on zero-hours arrangements for operational flexibility will need to either accept that pattern becoming contractual or restructure rotas to avoid regularity. Both approaches carry cost and administrative implications.
Review your workforce composition before implementation. Zero-hours usage is not uniformly problematic — some workers genuinely prefer flexibility — but where it is being used to avoid employment cost and legal risk, that model will need to change.
Workforce planning and cost implications
The combined effect of these reforms is to increase the average cost and legal risk of employing people, particularly for lower-paid and variable-hours workers. Employers should update their hiring cost models to include a higher provision for probation management, performance process time, and potential settlement costs for early-stage dismissals.
Structured onboarding and probation programmes, which are good practice regardless of legislation, become more valuable once unfair dismissal protection starts after six months rather than two years. Employers who already run well-documented probation processes will see less disruption than those who rely on informality.
Use the time before 1 January 2027 to complete the gap review: contracts, handbooks, probation policies, manager training, flexible working procedure and zero-hours audit. Set one deployment date for updated documentation so that all managers are working from the same version.
Building a compliant cost model
Every significant employment law change creates a corresponding administration cost that rarely appears in headcount budgets. Estimate the time cost of better probation management, more flexible working requests, guaranteed-hours reviews and any workforce consultation requirements. That time has a real payroll value.
Where the legal risk of dismissing someone after six months' service is real (for example, a hire into a business-critical role that does not work out within a few months), model a potential settlement scenario alongside the direct employment cost. Having that number visible in advance makes the decision to hire, or to take legal advice, faster.
Track compliance ownership clearly across HR, payroll and line management. When policy changes interact with payroll rules, out-of-date processes create avoidable errors. Assign named owners for each area of the reform and review compliance quarterly for the first year.
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