In regulations published on legislation.gov.uk, the government has now set the timetable for the next unfair dismissal changes under the Employment Rights Act 2025. The main provisions linked to section 25 and Schedule 3 will take effect on 1 January 2027, giving employers a firm date to work back from. This is a commencement measure rather than a full policy paper, but that does not make it minor. These regulations decide when the new legal position starts to matter in live cases, and that is exactly the point HR teams, founders and finance directors need to watch.

There are two dates in play. A limited part of section 25(5), alongside paragraph 5 of Schedule 3, comes into force on 1 July 2026. The explanatory note says that earlier move is mainly there so further consequential amendments can be made, including changes connected to the repeal of section 124 of the Employment Rights Act 1996. For most employers, 1 July is a technical milestone rather than an operational shock. The date with the clearest day-to-day effect is 1 January 2027, when the remainder of section 25 and the related consequential amendments are due to begin.

The legal wording is dense, as commencement instruments often are. Still, the broad point is clear enough: the unfair dismissal reforms in section 25 are moving from the statute book into live operation, including provisions linked to qualifying period and compensation. That gives businesses the rest of 2026 as a preparation window. Firms with frequent hiring, probation reviews or restructures should use it to check policies, manager training and template letters, because a dismissal started in late 2026 may end under rules that apply in early 2027.

The most important passage for live disputes sits in regulation 4 and turns on the "effective date of termination". In plain English, the law is not concerned only with the day an employee is told they are being dismissed. It is concerned with the legal date their employment actually ends. That means some cases begun before the new year can still fall inside the new regime. If an employee is dismissed before 1 January 2027 but their employment ends on or after that date, the amendments listed in the regulations can apply. A December notice period that runs into January is the obvious example.

The reverse rule matters just as much. If the effective date of termination falls before 1 January 2027, the new amendments do not apply, even where the wider process is close to the changeover point. For employers, that puts unusual weight on dates that might otherwise be treated as admin detail. A week or two in notice periods could decide which legal framework governs a case. That is especially relevant for SMEs, where year-end staffing decisions are often handled at pace and with limited in-house legal support.

There is also a narrower saving provision in the same regulation. It says the amendment made by section 25(4) of the 2025 Act does not disturb regulations already made under section 209(5) of the Employment Rights Act 1996 as that subsection stood before the change. That may sound remote from day-to-day management, but it is a reminder that employment law rarely switches from old to new in one clean step. During transition periods, the detail around preserved rules and commencement dates can matter as much as the headline reform.

The regulations were signed by Kate Dearden, Parliamentary Under Secretary of State at the Department for Business and Trade, on 26 May 2026. The accompanying note also points readers to the impact assessments prepared during the passage of the Employment Rights Bill, which look at costs for business, the voluntary sector and the public sector. For employers, the sensible response is preparation rather than alarm. The next few months are a chance to map any dismissals that may end in early 2027, tighten record-keeping around termination dates and make sure managers understand the timetable. For workers, the same calendar matters because a case ending in January 2027 may be judged differently from one that ends in December 2026.