As far as I know the registering part is mandatory for legal use but lets the accepting party decide to check it or not. For instance as you point out for bank

As far as I know the registering part is mandatory for legal use but lets the accepting party decide to check it or not. For instance as you point out for banks you can open an account without any check (you’re giving them money) but you won’t get a mortgage without proof of registration (they’re taking the risk) At a previous company my boss had his company stamp (a shachihata) in a drawer for us to use when he’s not there. It’s interesting because by the rule of law we would be the one in fault for using someone’s stamp, so it better be for stuff he approved verbally or other ways.