I never put banking information on my estimates, and only hand over that information when a PO has been generated and they want to pay via a bank transfer.
But anyway, how would they go about scamming you with that information anyway? They can't withdraw funds without your access, only deposit funds, right?
I have heard of scams where someone will give you a bad check that is in an amount hire then what was quoted and ask for the difference back. Of course, by the time the check bounces, they have your money and are long gone. With a transfer though, I am under the impression that the money needs to be in their account and is verified prior to the transaction. Meaning as soon as you receive notice of the funds being transferred, the money has been moved (unlike a check that takes one to two weeks to clear and the notice the day after depositing is just a courtesy). Is this correct?