The key changes employers need to prepare for
The Employment Rights Act 2025 introduces the most significant expansion of employee rights in a generation. The headline change is the removal of the two-year qualifying period for unfair dismissal claims, making unfair dismissal protection a day-one right for most employees. The practical implication is that probation periods will need to be better managed and more consistently applied.
Other significant changes include: flexible working becoming a default right from day one; zero-hours workers gaining the right to guaranteed hours contracts based on their regularly worked pattern; third-party harassment rules being strengthened; and trade union access rights being expanded.
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.
Day-one unfair dismissal: practical implications
Once day-one unfair dismissal protection is in force, employers cannot simply dismiss employees during a probation period without following a fair process. The government has indicated that probation periods of up to nine months will be the relevant framework, with a statutory procedure expected to apply during that window.
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 as legal protection for day-one rights. Employers who already run well-documented probation processes will see less disruption than those who rely on informality.
Use the next six months before implementation 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 day-one dismissal 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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