Do I have to pay a fee for all of my hospital/healthcare customers? Maura December 24, 2018 14:31 Follow You will only be required one signup & fee for all of a client's network hospitals. Related articles Is there a cost to the vendors to sign up for VendorProof? What happens if I don’t sign up? List of CHS hospitals How often do I need to log in to VendorProof? How do you determine who is a vendor? Comments 0 comments Please sign in to leave a comment.