What can you actually do about bullying at work?
More than people think, though the legal position is less straightforward than expected: there is no standalone legal claim for "bullying" in the UK, and what protects you depends on what the behaviour is connected to.
The legal landscape:
Harassment related to a protected characteristic — age, disability, gender reassignment, race, religion or belief, sex, sexual orientation — is unlawful discrimination, and this is the strongest route.
Bullying unconnected to a protected characteristic has no dedicated claim. It may still found a constructive dismissal claim where it breaches the implied term of trust and confidence and you resign in response — a high-risk route requiring you to leave.
Harassment law outside employment can apply to a course of conduct.
Health and safety duties cover risks to mental as well as physical health, and stress is within them.
Employer liability extends to acts of employees in the course of employment, which is why raising it formally matters.
What actually constitutes bullying: persistent criticism aimed at the person rather than the work, exclusion, humiliation in front of others, setting impossible deadlines, removing responsibilities without explanation, excessive monitoring, and spreading malicious rumours.
What is not bullying, and distinguishing this matters for a credible complaint: legitimate performance management, reasonable instructions, constructive criticism, and a single instance of rudeness.
What to do, in order:
Keep a contemporaneous record — dates, what was said, who was present, the effect on you and on your work. This is the single most valuable thing, because bullying is cumulative and any individual incident sounds trivial.
Check the policy, since most employers have a dignity at work procedure.
Raise it informally first where safe, which policies usually require.
Raise a formal grievance in writing, setting out incidents and the outcome sought.
Involve a union representative if you have one, or a colleague — you have a right to be accompanied at formal meetings.
Look after your health, and see a doctor if it is affecting you, which also creates a record.
Get free advice from ACAS, a union or a law centre before resigning. Do not resign first, since that removes most options.
General information, not legal advice.