I haven't the faintest idea which various other countries may require, what is your point? If necessary I would certainly do my best to know. No doubt custardpsc you will enlighten us all, that is, if you know yourself
It is not UK law that a business has public liability insurance, true, I never said it was but it is normal that you do have it when you are a business. Often it is the landlord or a contractor that will demand it. If you are a member of a professional trade association it may be required. The bank may want to see it if you apply for a business loan. Be in no doubt customers and members will be appalled to discover that the club does not have insurance that protects them.
However you may wish to view it, it is best practice. In the case of flying you must be insane not to have public liability because you could be ruined. It is law to have employers liability in the UK.