It would be helpful if the BT Broadband account holder could nominate one sub-account to have free access to the hotspots, in addition to the main e-mail account.
A parent could nominate a young person who may be away from home, at university or college.
This would avoid the need for the primary e-mail account details to be revealed.
The account holder would still be responsible for hotspot usage, and could suspend the access if needed.