I'm trying to pull the shipping tax code from invoices on a transaction search and its telling me the {shippingtaxcode} field cannot be found on my results column. The field is clearly there, and the field is correct, anyone know if there is a way to get this?

Fields on the record are not the same as search fields.

shippingtaxcode

is not documented as valid search column in the record browser (https://system.netsuite.com/help/helpcenter/en_US/srbrowser/Browser2019_2/script/record/transaction.html). Probably the shipping would be it's own result row.