Portable account number for consumer payment account

A method for processing a transaction, the method comprising:

• receiving, by a server computer from a point of sale terminal, an authorization request message for the transaction, the authorization request message comprising an account identifier data string associated with an account, wherein the point of sale terminal obtained the account identifier data string, and not information identifying an issuer for the account, from a payment device, the account identifier data string identifying the account used to conduct the transaction, wherein the account identifier data string associated with the account is an issuer-independent and portable account identifier that is used for processing the transaction;
• determining, by the server computer, the issuer for the account based on an issuer identifier data string, which is separate from the account identifier data string and identifies the issuer for the account, by accessing a database comprising a lookup data that contains an association between the issuer identifier data string and the account identifier data string;
• reformatting, by the server computer, the authorization request message to include the issuer identifier data string in addition to the account identifier data string, according to the issuer;
• routing, by the server computer, the reformatted authorization request message comprising the account identifier data string and the issuer identifier data string to an issuer computer operated by the issuer, wherein the issuer computer approves or denies the authorization request message and thereafter generates an authorization response message;
• receiving, by the server computer, the authorization response message;
• and
• forwarding, by the server computer, the authorization response message to the point of sale terminal,
• wherein the issuer-independent and portable account identifier is decoupled from the issuer, and
• wherein the issuer-independent and portable account identifier is configured to be associated with another issuer, in conducting another transaction.

A non-transitory computer-readable medium storing instructions which, when executed by a processor, cause the processor to perform a method of processing a transaction, the method including:

• receiving, from a point of sale terminal, an authorization request message for the transaction, the authorization request message comprising an account identifier data string associated with an account, wherein the point of sale terminal obtained the account identifier data string, and not information identifying an issuer for the account, from a payment device, the account identifier data string identifying the account used to conduct the transaction, wherein the account identifier data string associated with the account is an issuer-independent and portable account identifier that is used for processing the transaction;
• determining the issuer for the account based on an issuer identifier data string, which is separate from the account identifier data string and identifies the issuer for the account, by accessing a database comprising a lookup data that contains an association between the issuer identifier data string and the account identifier data string;
• reformatting the authorization request message to include the issuer identifier data string in addition to the account identifier data string, according to the issuer;
• routing the reformatted authorization request message comprising the account identifier data string and the issuer identifier data string to an issuer computer operated by the issuer, wherein the issuer computer approves or denies the authorization request message and thereafter generates an authorization response message;
• receiving the authorization response message;
• and
• forwarding the authorization response message to the point of sale terminal,
• wherein the issuer-independent and portable account identifier is decoupled from the issuer, and
• wherein the issuer-independent and portable account identifier is configured to be associated with another issuer, in conducting another transaction.