Redundancy in the UK is governed primarily by the Employment Rights Act 1996. Section 139 defines redundancy narrowly: a dismissal counts as redundancy only where it is attributable wholly or mainly to the employer ceasing business at the workplace, or to the requirements of the business for employees to carry out work of a particular kind having ceased or diminished. The House of Lords settled the test in Murray v Foyle Meats Ltd [1999] UKHL 29, confirming it is purely functional: the question is simply whether the business needs fewer people to do the relevant work, not what an employee's contract or job title says. An employer who labels a personality clash or a performance problem as "redundancy" is exposed the moment that label is tested.
Once a genuine redundancy situation exists, fairness is judged under section 98(4). There is no statutory ACAS Code of Practice for redundancy in the way there is for discipline and grievance, so the standard comes from case law. The leading authority remains Williams v Compair Maxam Ltd [1982] IRLR 83, where the Employment Appeal Tribunal set out the principles a tribunal expects: maximum warning, consultation with representatives or affected individuals, selection against criteria that can be objectively checked rather than personal opinion, consistent application of those criteria, and a genuine search for alternative employment. The ACAS non-statutory guidance on redundancy fleshes these out in practice, and the official ACAS guidance on collective consultation for redundancy is the reference point for employers near the 20-employee threshold.
Two further rules bite directly. Section 86 ERA 1996 sets statutory minimum notice at one week per year of service up to twelve weeks, or the contractual period if longer. Section 138 gives an employee who accepts suitable alternative employment a four-week statutory trial period before redundancy pay is affected. Where 20 or more dismissals are proposed at one establishment within 90 days, sections 188 and 193 of the Trade Union and Labour Relations (Consolidation) Act 1992 impose collective consultation and a Form HR1 notification to the Secretary of State, with a 30-day minimum consultation window. The Employment Rights Act 2025 will add an organisation-wide trigger from 2027, but the establishment test survives. This pack covers the sub-20 individual route, where collective duties do not apply but the Williams standard does.