In this case there is different mechanism to link up their tax codes with country-specific tax report.
First of all, they should see country-specific report after selecting the country.
But this report will show zeroes. To link it up with their existing tax codes, they need to select correct reporting category when editing their existing tax code.
However, for Dutch and 4 other countries, I still need to finalize transition into reporting categories. There are no reporting categories yet. Instead, there is a custom field (the bottom of the form) which needs to be filled in.
