Keep an empty bag in bank, i auto bank something. If it go to empty bag, i do not have this item in Bank, or a stack is completed in bank. Once a stack is full, i move it by shared bank to another mule. And for keep track of my inventory, i use outputfile command, excel and a legal macro programme (as it do not touch EQ) for collect data, create a code and upload it on a page. So i can check or search for something on 65 differents chars. Potentially, you can have millions of chars account. The limit is your computer limits.