The Homeowners Alliance gives top tips on finding the right removals company and their first tip is "Is the company a member of either the BAR (British Association of Removers) or PMA (Professional Movers Association)? These are the closest thing to a governing body for removal companies in the UK".
If I take this literally, that means I should ignore companies that are members of the National Guild of Removers instead. I have no idea whether these various schemes are equivalent to each other or not, but from what I've seen, companies tend to be affiliated to one, rather than all, of them.
Advice appreciated!