Customer list incomplete

I want to submit my customer list, but the list is incomplete. The customers for whom I created invoices are in the list. There is also a customer for whom I entered the income via Daily receipts (amount above 250 euros). Here, I did not have to indicate from whom this income came, so the customer is not stated in the list. How can I solve this? Is there a template I can use to create a list myself? What information (e.g. company number) is required for each customer in the list, so that I am sure I don’t forget anything? Thank you for your help!