You can pull up the Customer Contact List report to include the identifier. Let me walk you through the steps on how to export a list.
Once done, an Excel Spreadsheet will open where you can view your list.
Feel free to read this article for more information: Export reports, lists, and more.
You can also visit this link for future reference: https://quickbooks.intuit.com/community/Reports-and-accounting/bd-p/reports-account?label=QuickBooks....
If there's anything else I can help you with, please don't hesitate to post anytime.