If he has social welfare free travel pass with photo, that may suffice.An elderly relative wants to buy saving certs/bonds and has no longer got a driving licence or passport. Does he need an ML 10 form for i.d
Unfortunately it seems to depend upon where you go.
A few years back when I opened a new bank account the official (a senior one) declined my bus pass. I politely told her to ring head office. She was very apologetic when she returned.