Transaction ID

This 15-character field contains the Transaction Identifier associated with the transaction being settled. Additionally:

• If the transaction was authorized online, this field must contain the value (if returned) from the original authorization response message.
• If the Transaction Identifier received in the original authorization response message is less than 15 numeric digits, left-justify and space-fill to 15 bytes in this field.
• If a value was not returned in the authorization response or the transaction was processed offline, this field must be defaulted to zeros.