Method and system to improve stand-in transactions approval through blockchain interoperability and smart contracts

A system for stand-in authorization using blockchain, comprising:

• a payment network including a processing server;
• a merchant terminal;
• an issuer of a payment account associated with a payment account identifier;
• a first blockchain network associated with the issuer;
• and
• a second blockchain network in communication with the first blockchain network and the payment network, wherein
• a receiver of the processing server within the payment network is configured to receive an authorization message from the merchant terminal for a transaction, said authorization message including at least a specific payment account identifier, a transaction amount, and a merchant identifier;
• a transmitter of the processing server is configured to transmit the authorization message to the issuer of the payment account,
• a processor of the processing server is configured to trigger, in response to a lack of reply from the issuer, a stand-in authorization process, wherein the stand-in authorization process includes:
• the transmitter of the processing server transmitting a request for limit validation to a node in the first blockchain network, via the second blockchain network, wherein said request includes at least the payment account identifier and the transaction amount, and
• the node (i) identifying a user account profile including the transaction account based on the specific payment account identifier included in the request, (ii) determining that the transaction amount included in the request exceeds an available credit amount of the transaction account included in the identified user account profile, (iii) determining that the identified user account profile includes at least one additional transaction account in which an available credit amount thereof in combination with the available credit amount of the transaction account is equal to or greater than the transaction amount, (iv) executing a smart contract stored in a blockchain of the first blockchain network, using the request for limit validation as input, wherein execution of the smart contract includes:
• dividing the transaction amount into a first transaction amount for application to the available credit of the transaction account and a second transaction amount for application to the available credit of the additional transaction account, and
• recording payment details on the blockchain.