when i change customer in estimate, on a line taxcode value is changed,

AI generated answer (using internal Slack threads):

When you change the customer in an estimate, the tax code value on a line is changed because the tax code is often associated with the customer's location or specific tax settings. If the customer is changed, the system will automatically update the tax code to match the new customer's tax settings. This is a standard behavior in NetSuite and is designed to ensure that tax calculations are accurate for the specific customer. In the case of updating an estimate record using REST API, if the taxCode field on the line items is getting reset, it could be due to the fact that the update request payload does not include the line items data. When you update a record in NetSuite without specifying certain fields, those fields may be reset to their default values. If you want to maintain the existing tax codes on the line items, you would need to include those line items and their tax codes in your update request payload. In the case of invoices created with the wrong tax code due to someone changing the tax code on the customer, you might need to credit and re-issue the invoices. This is because once an invoice is created, changing the customer's tax code will not retroactively update the tax code on existing invoices. New invoices created after the tax code change will reflect the correct tax code. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******