The UK’s Employment Rights Act 2025 is the most significant change to employment law in a generation. It received Royal Assent in December 2025. Its provisions are rolling out across 2026 and 2027. And for anyone acquiring, integrating or restructuring a business in the UK, the rules of engagement have fundamentally changed.

This matters. Not because employment law is a niche concern to be delegated to HR. It matters because the Act directly affects deal economics, integration timelines and the risk profile of acquisitions in the UK. And the cost of getting people decisions wrong has risen materially.

What does the Employment Rights Act mean for acquirers, integration leaders and the senior HR professionals navigating transactions on the ground?

Ben Cowan, Head of Consulting at Eton Bridge Partners, sat down with David Boyd, Consulting Partner and author of M&A Playbook: The Art & Science of Integration, and Lydia Heyworth, Managing Partner of Echelon Advisory Group, to discuss its impact on M&A execution and integration.

The following sets out their analysis of the key provisions, the risks they create, and what businesses need to do now.

What has changed

The headline changes arrived in April 2026. Statutory Sick Pay is now payable from day one of absence. Paternity and parental leave are day one rights. The maximum protective award for failing to consult properly on collective redundancies has doubled, from 90 to 180 days’ gross pay per affected employee. A new Fair Work Agency has launched to enforce compliance. And employers must now keep formal records of annual leave entitlement.

More is coming. From October 2026, employers face a strengthened duty to prevent sexual harassment, including from third parties. The time limit for employment tribunal claims extends from three to six months.

Changes that will reshape M&A then arrive in January 2027.

First, the qualifying period for unfair dismissal claims falls from two years to six months. Anyone employed from July 2026 onwards can exercise claims under the new rules from 1 January 2027.

Second, the compensation cap for unfair dismissal is removed entirely. The current cap sits at approximately £120,000 or 52 weeks’ gross pay.

Third, fire and rehire becomes automatically unfair in most circumstances. Dismissing an employee for refusing changes to core contractual terms covering pay, pensions, working hours and shift patterns will be automatically unfair, with only a narrow exception for severe financial distress threatening business viability.

Finally, the act introduces stricter holiday pay enforcement, requiring employers to maintain accurate records of entitlement and pay. Crucially, enforcement bodies can now review up to six years of retrospective records, significantly increasing exposure to backdated claims. Any historic underpayment of holiday pay could trigger substantial liabilities.

Why uncapped compensation is the headline

Compensation caps are the global norm. France, Spain, Italy, Ireland, Australia and Switzerland all operate within defined limits. Most European jurisdictions deliberately balance predictability for employers with fairness for employees.

Every senior exit in the UK now carries potentially unlimited financial exposure.

Financial services and professional services firms will struggle with this. Higher earners historically avoided employment tribunals because a negotiated exit package would incorporate a sum equivalent to the cap. That calculation is now much harder: even where claims do not proceed to full hearings, the negotiating dynamic shifts materially in the employee’s favour.

For acquirers planning post-deal leadership changes, it means repricing each senior exit on each deal.

What this means pre-deal

Due diligence scope must expand. The standard People DD checklist needs updating. Beyond existing liabilities, acquirers need to assess the target’s readiness for the incoming reforms. Are probationary periods set at six months? Is performance management documented to a standard that would withstand tribunal scrutiny?

The Share Purchase Agreement (SPA) needs new protections. Warranty and indemnity provisions should explicitly address the Employment Rights Act. Specific indemnities for non-compliance with the new consultation requirements, uncapped dismissal exposure for key personnel, and the cost of implementing compliant processes should be negotiated.

Valuation models need repricing. Cost synergies from headcount reduction will be more expensive to realise. Longer consultation timelines. Higher protective awards. Uncapped dismissal risk for senior roles. Each integration budget needs to reprice the cost of redundancies.

What this means post-deal

Integration timelines extend. The era of fast, aggressive headcount reduction post-close has become significantly more expensive. Collective consultation timelines need to be built into integration plans before completion… the doubled protective award of 180 days’ gross pay per affected employee is the penalty for getting this wrong.

Organisation design and selection processes must be watertight. With a six-month qualifying period and uncapped compensation, the quality of your process matters. Every role elimination, every selection exercise, every performance-managed exit needs to be documented, defensible and fair. Cutting corners on organisation design is no longer a shortcut. It is a liability.

Retention gets harder and more important. The people you want to keep have more protection and more options. The people you need to move on are more expensive to exit. Getting retention right, early, with clear incentives and transparent communication, needs more time and attention.

TUPE: Not changed yet, but watch this space

TUPE itself is not directly amended by the Employment Rights Act. But the ERA changes the environment around TUPE in ways that matter.

The most immediate impact is the shorter qualifying period for unfair dismissal. Under the old two-year rule, many TUPE-transferred employees with short service had limited tribunal rights. The fire and rehire restrictions also bite on post-TUPE harmonisation. The boundary between a TUPE-related change and a general contractual variation is often contested. The new restrictions narrow the room for manoeuvre considerably.

And the direction of travel is clear. The government launched a formal call for evidence on reforming the TUPE regulations in April 2026. It is explicitly seeking to strengthen the existing protections.

Context: The UK compared

It would be easy to read this legislation and conclude that the UK is becoming hostile to acquirers. That would be wrong. The UK occupies a middle ground: more protective than the US employment-at-will model, less onerous than the Netherlands, where sick pay obligations can run for two years and termination during that period is prohibited. Competitive valuations and a deep talent pool make the UK an attractive acquisition market. The new employment rights raise the stakes on getting people decisions right – but the deals are there for those prepared to do them well.

Practical timeline for acquirers

The good news: Technology is changing the game

Here is where the narrative shifts. The same legislation that increases the cost of getting integration wrong arrives at a moment when we have dramatically better tools to get it right.

McKinsey’s January 2026 survey of M&A practitioners found that those using generative AI in dealmaking reported roughly 20% cost reductions and significantly faster deal cycles. However, adoption is uneven. Most AI investment has concentrated on pre-deal activity: target identification and due diligence. This is where the tools are most mature. Integration planning (pre and post deal) as well as execution still lags well behind. That is a problem, because integration is exactly where the Employment Rights Act has raised the stakes on people decisions.

McKinsey found that only 30% of practitioners engage with AI at even moderate levels, and most of those are still using off-the-shelf chatbots rather than tools purpose-built for deal work. This matters because integration is where the legislation bites hardest, and it is also where AI can now make a practical difference.

AI is transforming how integration teams operate, in practice, right now.

In practice, this means stakeholder maps and communications plans that take hours rather than weeks; retention modelling across compensation data, employment terms and market benchmarks that improves package quality when the cost of getting senior exits wrong has never been higher; and employee Q&A preparation thorough enough to anticipate hundreds of questions before they are asked. The integration team refines and personalises rather than building from scratch.

The increased effort required to retain and manage people through an integration is partially offset by the increased capability that AI provides.

AI is also making a practical difference in the pre-deal phase, with outputs that are specific and deal-relevant. Integration feasibility assessments can now be produced in days rather than weeks, giving deal teams early sight of what protects and destroys deal value from an integration lens: potential failure modes and their commercial consequences, insights for the investment case, areas that need funding, and considerations for integration design and sequencing.

Cultural assessments can compare acquirer and target cultures early enough to inform deliberate decisions on culture design, what shifts should take place, and where friction will arise, while there is still time to factor the findings into deal terms, integration planning and resourcing. Integration frameworks and playbooks can provide the structure for organisations to absorb the integration alongside existing commitments.

The critical point is that AI does not replace integration expertise. It amplifies it.

Some AI tools now being marketed to teams have been built without deep integration experience behind them. They can summarise documents and generate templates, but they don’t understand the judgement calls that determine whether an integration succeeds or fails.

The acquirers who will benefit most are those working with practitioners who bring both: real deal experience and the technology to deliver it at speed to protect and achieve deal value. That is the combination Eton Bridge Partners brings to every engagement.

What to do now

The April 2026 provisions of the act are now live, and we have only 9 months until the full January 2027 provisions are in place.

For acquirers with active deal pipelines, the actions are clear. Expand People DD scope to assess readiness. Reprice synergy models to reflect increased restructuring costs. Build realistic consultation timelines into integration plans before completion. Negotiate SPA protections that reflect the new risk environment. And invest in the tools and processes that make rigorous people management achievable at pace.

The UK remains an attractive market. The deals are there. What has changed is the cost of doing them carelessly. Getting people decisions right across the full M&A lifecycle requires the right expertise at the right time.

Eton Bridge Partners works as a trusted partner throughout that journey bringing senior consulting experience, interim leadership capability and the technology to deliver. If you are working through an active deal or building the integration capability to handle what is coming, we would welcome the conversation.