The invention provides systems and methods within existing business and technology infrastructures and processes for facilitating an electronic transaction including payment by an account issuer to a merchant for online purchases by a consumer. The invention uses a web services model including request and response messages to provide simplified authentication and authorization through entry of the consumer's PIN, without the release of the consumer's account or billing information to the merchant. The invention reduces authorization processing, and reduces the transaction fees for online transactions, increasing the viability of lower value transactions.