Payment real-time funds availability

A method being implemented via execution of computer instructions configured to run at one or more processors and configured to be stored at one or more non-transitory computer-readable media, the method comprising:

• receiving a first promise-to-pay message at a second financial institution, the first promise-to-pay message being based on a successful debit of a first account maintained by a first financial institution, the successful debit of the first account being based on a payment authorization for a payment amount made by a sender at a payment authorization time, and the first account being held by the sender;
• performing a successful credit for the payment amount to a second account maintained by the second financial institution to make funds available in the second account in real-time after the payment authorization time, the sender being financially liable for the second account;
• and
• sending a first response from the second financial institution indicating the successful credit of the second account maintained by the second financial institution to inform at least the sender in real-time after the payment authorization time of the successful credit of the second account maintained by the second financial institution,
• wherein:
• the first financial institution is different from the second financial institution;
• the first financial institution maintains a first settlement account;
• the first settlement account is credited after the successful debit of the first account maintained by the first financial institution to account for the successful debit of the first account maintained by the first financial institution;
• the second financial institution maintains a second settlement account;
• the second settlement account is debited before the successful credit of the second account maintained by the second financial institution to account for the successful credit of the second account maintained by the second financial institution;
• the successful credit of the second account maintained by the second financial institution involves a hard credit to the second account in real-time after the payment authorization time;
• settlement funds are transferred from the first settlement account to the second settlement account in a settlement completion after the payment authorization time, after sending the first response, and after the hard credit to the second account;
• the first promise-to-pay message is received at the second financial institution from a transaction system based on a second promise-to-pay message sent from an application service provider to the transaction system;
• the application service provider is in data communication with the transaction system;
• the transaction system is in data communication with the second financial institution;
• the transaction system is maintained by an entity that is different from the application service provider, the first financial institution, and the second financial institution;
• and
• the first response is sent from the second financial institution to the transaction system, such that a second response is sent from the transaction system to the application service provider indicating the successful credit of the second account maintained by the second financial institution, and such that the application service provider informs the sender in real-time after the payment authorization time of the successful credit of the second account maintained by the second financial institution.