Since the ID is really for money laundering avoidance it is possible to get an exemption. Banks have misinterpreted the rules. He must at least have proof of address via a letter from his landlord and he must have a National Insurance Card as everyone is issued with one now. Applying for a passport is the best route to go as it will be necessary for many other things as well. I was able to apply for an exemption for my mother who does not have a passport or driving licence or even a firearms certificate ( thank god! ) so it is possible.