How to stop leads from showing up in the list of customers when entering an invoice

AI generated answer (using internal Slack threads):

To stop leads from showing up in the list of customers when entering an invoice, it's important to note that in NetSuite, creating an invoice automatically converts a lead/prospect into a customer. Therefore, it's unusual to have a customer still listed as a lead/prospect after invoicing. However, if you're still encountering this issue, you might want to review the cause. One possible solution could be to use the customer Status field to filter out leads and prospects. Please note that you cannot change the filtering on a standard field. If you were to limit the options available in the standard Customer field on the Invoice form, it would disrupt the native flow of NetSuite. For instance, selecting a Lead or Prospect in the Customer list to create their first invoice would no longer be possible. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******