The present invention provides a system and method for providing and/or facilitating complete on-line payment services while protecting the privacy of the transaction participants. The comprehensive payment service is based upon a consolidated account used to store value acquired through on-line transactions. The invention provides private payment numbers for protecting the identities of the participants and includes processes for authenticating participants, authorizing transactions, and settling payments. Thus, the present invention enables merchants to effectively accept non-standard forms of payment without changing their current payment infrastructures and enables the provision of value for purchases at any network merchant using any source of value.