How are you guys assigning specific tax codes to item records when Advanced Taxes is enabled? We are One World account and Advanced Taxes is enabled by default. We cater to international customers so we created multiple nexuses and tax codes. However, we cant seem to assign tax codes to items. Any ideas?

I think in advanced taxes you assign tax schedules to items. Then you assign nexuses as taxable or non taxable to the tax schedules

yeah that's right - for each tax schedule you create a default rate for each item However you should still be able to override the tax code (tax group in CA and US) on an item line, the only restriction is that the customer or vendor must be present in the appropriate nexus (this is based on shipping country/state in most cases).