This document assumes the following:
Enrolmy Generated Invoices & Credit Notes
Enrolmy generated invoices and credit notes will always have your organisation name's acronym as the invoice number prefix.

Xero Generated Invoices & Credit Notes
Xero generated invoices and credit notes will not have your organisations title acronym as the invoice/credit note prefix.
Great! You can clearly distinguish between Xero invoices and Enrolmy invoices!