when importing bill payments with header and lines files i receive this record already exists error

AI generated answer (using internal Slack threads):

The "This record already exists" error typically occurs when you are trying to import a record with an external ID that already exists in the system. If you are using the "Add" or "Add or Update" option during the import and the external ID already exists, you will encounter this error. However, if the external ID does not exist prior to the import, you should not encounter this error, regardless of how many times the external ID repeats in the CSV file (as it is still considered one transaction). Another possible cause of this error could be that your CSV file is not sorted correctly. For example, if lines 1, 2, and 3 appear together but line 4 appears further down in the CSV, this could cause the error. When importing bill payments, the error "Unable to find a matching line for sublist apply with key" typically means that NetSuite is unable to find a bill to pay in the exact amount of the payment you are uploading. If there is even one line that is incorrect in a payment CSV file with multiple lines, the entire file will fail. To troubleshoot this, you could run a saved search against the bills you are trying to import against, and expose the External ID for the lines, and ensure that matches your upload file of Bill Payments. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******