The Transaction Link Identifier (TLID) is a unique transaction identifier generated by Mastercard to provide a more consistent method for linking related activity after the original authorization. The TLID is generated by Mastercard, returned in the initial transaction lifecycle message, and included in all subsequent lifecycle messages.

Portico automatically associates the TLID from the original authorization on the merchant's behalf for subsequent transactions in which an original transaction ID reference is provided. Original references are:

• Client Txn Id
• GatewayTxnId
• Global Transaction Id

When an origianl transaction ID reference cannot be provided, the transaction services below can also receive a TLID in order to connect economically related activity to an originating transaction per Mastercard’s requirements

• CreditReturn
• DebitReturn
• RecurringBilling
• RecurringBillingAuth

The TLID is provided in the transaction request and returned in the transaction response in the TxnLinkId field.