When does the Billable field on a line item change from True to False?

AI generated answer (using internal Slack threads):

The Billable field on a line item in NetSuite changes from True to False based on the context of the transaction. If the Customer column changes on an Item or Expense for a Vendor Bill, the Billable checkbox automatically changes to true. This is a native NetSuite behavior. However, there are situations where you might not want it to be automatically ticked. Unfortunately, there is no direct way to control this behavior through scripts or workflows as it is a built-in feature of NetSuite. On the other hand, the Billable checkbox on a bill credit transaction line is used when you have a billable expense. It creates an offset - effectively a credit against the customer when you do the billable action. In the context of a sales order, you can bill a single line from a sales order provided the 'Invoice in Advance of Fulfillment' is not set to False under Accounting Preference > Order Management. If it's set to True, it fulfills all the line items instead of the one line even though the saved search is restricting to one line. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******