Apparatuses and methods to mask identification information to create billing mechanisms in an online listing system are disclosed. In one embodiment, a computer-implemented method of operating an online listing system includes determining an identity of a user based on an identifier entered by the user that uniquely identified the user; and capturing call history information when routing a proxy telephone number from the user (e.g., a renter, a buyer, a prospective buyer, a mortgagor, etc.) to a lister (e.g., a landlord, a seller, a rental manager, a mortgagee, etc.). The identifier may be the proxy telephone number and/or a code entered after dialing the proxy telephone number. The proxy telephone number may be converted to an actual telephone number prior to routing the proxy telephone number to the lister.