There maybe a way to make “Multiple rate” tax codes behave like three different single rate tax codes with a separate liability account and associated reporting for each component.
There was a way of grouping tax codes which was used for report transformation when new tax codes / rates replace a prior rate. I forget the details as I didn’t need to use it.
If it is not possible perhaps a different solution or enhancement maybe added for jurisdictions requiring multiple tax codes per line item and reporting to their tax authority (eg India, Pakistan, USA). As I don’t run business in those countries I may not be best placed to find an optimal solution.
I have suggested a system which internally uses multiple line level tax codes for all taxes but has a user interface allowing data entry and display at line or transaction level (invoice / payment / receipt). Added withholding tax support for purchase invoices - #26 by Patch and the idea thread Tax Withholding Percentage - #27 by Patch The idea was not popular but hopefully there is some other way of achieving the required flexibility and reporting for those who need it.