AI generated answer (using internal Slack threads):

The error message you're seeing, "*One or more selected items use a different tax rule than the others on this transaction. Transactions can only contain items with the same tax rules. Create separate transactions as required.*", is indicating that you have items in the same transaction that are using different tax rules. In NetSuite, each transaction can only contain items with the same tax rules. If you have items with different tax rules, you will need to create separate transactions for each set of items that use the same tax rules. For example, if you have items A, B, and C in a transaction, and items A and B use tax rule 1, and item C uses tax rule 2, you will need to create two transactions. One transaction for items A and B, and another transaction for item C. This is a limitation of the system and cannot be changed. If you need to apply different tax rules to different items, you will need to create separate transactions for each set of items that use the same tax rules. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******