I've similar questions to this a few times at the bank, the only appropriate answer is down the back of the sofa, underneath the mattress, drug dealing or the magic money tree
I remember people complaining about HSBC started doing this a while back for cash withdrawals.
It was not long after they'd been exposed for helping cartels and terrorist launder their money. So I like to imagine that lots of customers gave smart-arsed replies referencing that.
I've similar questions to this a few times at the bank, the only appropriate answer is down the back of the sofa, underneath the mattress, drug dealing or the magic money tree