Persons with significant control
The UK register of who really controls a company.
Persons with significant control, usually abbreviated PSC, is the United Kingdom register recording who ultimately controls a company. A person or corporate entity must be registered if they hold more than 25% of shares or voting rights, can appoint or remove a majority of directors, or otherwise exercise significant influence.
It is free to search and, unlike a company's own statements, a legal filing. For privately held British companies it is often the only public evidence of corporate parentage.