Please allow group sharing / pooling / transfer of data allowance
If you have multiple family sims with a monthly data allowance in a group plan, some sims may run out of data while on other sims, there is remaining data. Please allow group data allowance to be shared / transferred / pooled. An enquiry has been made about this at least once before: https://community.smarty.co.uk/t5/chats-hacks/can-group-data-be-shared/m-p/3728