Originally Posted by dnw
In fact this is the correct answer. Only one 'active' account required per household.
DNW is correct. Only one member of the household account has to have activity in a 36-month period to extend the miles of all other members of the account for another 36 months. I received this answer over the phone; then decided I wanted it in writing (hopefully worth something), so have that from BA as well, dated less than a week ago.