# Order number management

> Explain how to manage order numbers when integrating with acquirers through APO, detailing required parameters and their use in reconciliation and dispute handling.

After integrating with acquirers through APO, the management of order numbers has changed compared to when you integrate directly with an acquirer. You need to maintain an appropriate order number system based on the different integration methods:

-   **Connecting directly with acquirers**: You must manage the following parameters:

-   _merchantId_
-   _paymentRequestId_
-   _acquirerInfo.acquirerTransactionId_.

-   **Connecting with acquirers through APO**: You must manage the following parameters:

-   _merchantId_
-   _paymentRequestId_
-   _paymentId_
-   _acquirerInfo.referenceRequestId_
-   _acquirerInfo.acquirerTransactionId_

## Use Cases for _acquirerTransactionId_

### Reconciliation

If you use the original reports provided by the acquirer for reconciliation, which typically include the acquirer-side order number, you need to store the information of _acquirerInfo.referenceRequestId_ and _acquirerInfo.acquirerTransactionId_. With this information, your finance team can match _acquirerInfo.acquirerTransactionId_ with _merchantId_, enabling streamlined reconciliation.

### Dispute

For card payments, you need to contact the correesponding acquirer to handle the dispute if it occurs. The acquirer can provide you with _acquirerInfo.acquirerTransactionId_. Use the following methods to obtain the information on _merchantId_:

-   It is recommended to save the information of _acquirerInfo.referenceRequestId_ and _acquirerInfo.acquirerTransactionId_returned by the API. Your operation team can query the corresponding _merchantId_ on the internal platform using _acquirerInfo.acquirerTransactionId._
-   Log in to APO Dashboard and search for _merchantId_ using _acquirerInfo.acquirerTransactionId._