The Acas Code requires a formal meeting, an impartial investigation, and a written outcome with an appeal option.
Act promptly—delays can escalate tensions—and keep detailed notes. If unresolved, it could head to a tribunal, so thoroughness matters. HR support can guide the process or train teams to handle complaints, minimizing legal risks. Listen actively in the meeting to show you’re taking it seriously, which can de-escalate emotions. Follow up with the employee after the outcome to ensure they feel heard and reduce repeat issues.
Helpful government guidance is available at: Handling an employee grievance on GOV.UK.