Systems and methods enable the real-time authorization of payment transactions initiated by personal and mobile computing devices. In one embodiment, a financial account server associated with a payment recipient, or payee, is configured to receive a payment data envelope from a payee computing device. The payment data envelope can originate from a payer computing device and include transaction information obtained from an identity management service associated with the payer. The payment data envelope can further include information that allows for the authentication of the payee and payer identities as well as payment instructions. The payee financial account server processes the payment data envelope and transmits the envelope to a financial account server associated with the payer. The payer financial server authenticates the payer identification, authorizes the payment transaction, and transmits a transaction status message to the payee financial server, which in turn transmits the message to the payee computing device.