Repeated, unreasonable behaviour towards you at work that undermines you or damages your dignity, such as persistent criticism, exclusion, humiliation, or intimidation. Bullying on its own is not automatically unlawful in the UK: there is no free-standing legal claim for it. If the behaviour relates to a protected characteristic such as your sex, race, disability or age, it becomes harassment instead, and the Equality Act 2010 applies. Even without that link, an employer can still be liable if sustained bullying causes you psychiatric injury, or if a mishandled grievance about it leads to constructive dismissal.
Sustained bullyingRepeated, unreasonable behaviour towards you at work that undermines you or damages your dignity, such as persistent criticism, exclusion, humiliation, or intimidation. Bullying on its own is not auto... is judged cumulatively, not incident by incident: in Green v DB Group Services (UK) Ltd, a High Court case, an employer was found liable for an employee's psychiatric injury caused by a pattern of small, spiteful acts from colleagues that built up over time, because it knew what was happening and failed to stop it.