What whistleblowing is (and isn’t)
Whistleblowing means reporting certain serious wrongdoing that is in the public interest — it affects others, not just you. In law it’s a “protected disclosure” under the Public Interest Disclosure Act 1998.
It is not the same as a personal complaint about how you are treated — that’s usually a grievance. The line is the public interest: does the wrongdoing affect other people, customers, the public or the environment?