When you remove a bank account, Prosper gives you this warning:
Removed bank accounts cannot be recovered
Once you have removed a bank account, you will be prohibited from adding another bank account with the same routing and account numbers again.
Isn't that a silly rule?
maybe they dont want to use resources to verify a bank account more than once?
Which would be different than using the resources to verify a new account?
*If* (big if) that's the reason, it is because verifying a bank account (used to - does it still?) consists of a two-step procedure to make a small deposit and a smaller withdrawal. In the time when the code was originally written, Prosper used to make two small deposits. That was later changed to the deposit/withdrawal method as a better test of the two-way capability of the information supplied.
Someone with a twisted mindset could do endless account verifications of the same account, making a general nuisance of themselves and making a tiny (very tiny) profit while costing Prosper some money to perform all those deposit/withdrawal ACHs.
This way they only get to verify a bank account once. If you want to tie up a lot of Prosper resources in account verification, you'll have to make a substantial effort that's not worth the trouble.