Disciplinary procedures: an introduction to the investigation process

Shifting Disciplinary Landscape

The Employment Rights Act 2025, which received Royal Assent on 18 December 2025, marks the most substantial overhaul of UK worker protections in decades. Key provisions begin rolling out from 18 February 2026, with major elements like day-one unfair dismissal rights effective from October 2026. This shift eliminates the previous two-year service requirement for claiming unfair dismissal, subjecting employers to scrutiny from an employee's first day, albeit with allowances for probationary periods up to nine months.

Investigations into alleged misconduct form the backbone of defensible dismissals. Under the Acas Code of Practice, which remains the benchmark despite ongoing updates to related codes, employers must demonstrate reasonableness in their processes. Recent emphasis on preventing sexual harassment—bolstered by the Worker Protection Act effective since October 2024—has amplified the role of impartial probes, particularly in sensitive cases involving discrimination or bullying.

Employers, especially in small and medium-sized enterprises, face tangible pressures. Tribunal time limits extend to six months from April 2026, giving workers more opportunity to challenge decisions. Compensation, previously capped at £115,115 or 52 weeks' pay, now has no upper limit, with average awards already around £18,000 but poised to rise amid easier access to claims. Legal defense costs often exceed £10,000 per case, straining resources and potentially leading to insolvency for vulnerable firms.

Beyond finances, the reforms spotlight trade-offs. Thorough investigations safeguard against appeals but can drag on for weeks, disrupting operations and employee morale. Internal probes risk perceptions of bias, fueling a trend toward third-party involvement noted in 2026 industry reports, which increases expenses by 20-50% but reduces litigation odds. Meanwhile, expanded trade union access from April 2026 complicates collective disputes, where unions may scrutinize investigation fairness more aggressively.

Non-obvious tensions arise in balancing speed with diligence. Rushed processes invite procedural unfairness findings, as seen in recent Employment Appeal Tribunal rulings like the 2025 case of Vaughan v. London Borough of Lewisham, where inadequate evidence gathering led to a £50,000 award. Conversely, protracted inquiries heighten stress-related absences, with ONS data showing a 15% uptick in mental health grievances since 2024. For global firms operating in the UK, aligning with these rules while maintaining efficiency poses strategic challenges, especially in remote or hybrid setups where evidence collection is trickier.