One of the best things that you can do when opening a new account for a vendor or customer is to make sure you get their banking information.  A copy of a check.  Anything with their bank account number and banking institution.

This is so helpful when you have to turn the matter over to an attorney.  It will give you an account to go after when you get a judgment against the debtor.

You can faciliate this by requiring a copy of a cancel check as part of the application process.