Hello,
To maintain the correct reporting for the past transactions, we recommend to set up a new tax code, instead of simply changing the tax rate of the currently used Tax Code.
To create new Tax Code with the appropriate % rate, please go to module General Ledger (Nominal Ledger in the UK version)>> Settings>> Tax Codes (VAT Codes) and create enter a new code, filling the relevant columns on all Flip (A to F). Please use the currently set up Tax Codes as examples.
Kind regards,
HansaWorld Support Team