We live in a rural community. Many of our customers do not have physical addresses and use PO Boxes. Here's my question: Once we have verified an individual through a proper ID, such as drivers license, and opened an account do we have to put a physical address on the BSA risk assessment form.
FrankB.

I think you should review your procedures to see what they say. I'm assuming that the Risk Assessment Form you are speaking of is an internal form? It is ok to have a mailing address and a physical address for a customer, but you must obtain a physical address. Where you document that is up to what your procedures say and what your systems will allow.

Also, keep in mind that CIP requires you to get a physical address, even if it's for a next of kin (unless they have an APO or FPO).

A description of where the customer lives will also suffice if no physical address is available. For example, "4.5 miles west of town, turn right on County Road ###. Second house on the left."
You have to know where to find your customer, not their mail, which is the reasoning behind the physical address requirement.
Check your institution's procedures for information on where to document it.