Re: an account number was accidentally entered into the payment amount field
I use a small random number
In the US when you link two bank accounts to allow transfers between them, they (at least in my experience) will do two small withdrawals and one credit, of random amounts which cumulatively add up to zero. In order to enable the transfers for real you have to enter the amounts of those transfers to demonstrate you have access to both bank accounts.
That way if you typo the routing number or account number those random transfers will go to someone else's account, and when you don't see them in the intended account will know you screwed up somewhere but at least you won't send real money into the ether!
That wouldn't fix entering the account number as the amount, but I guess I'm protected from that by being limited to $10,000 in transfers in a day. Which is fine most of the time, but sometimes I've had to do transfers over several days as a result, or am forced to use cashier's checks or wire transfers (the cashier's checks cost less for some inexplicable reason) for large amounts.
Biting the hand that feeds IT
