I have created a new Tax Type for HST. I want to export customers to change the Tax Type to HST, however, in the File Export in AR there is no option to export Tax Type. The only two options are Tax Group or Tax Status.

I also created a new Tax Group covering HST, however, I cannot get OE to calculate the taxes properly on the invoices. What am I doing wrong?

Tax Status is the field you want.

In OE, shipping addresses also contain tax statuses. You need to use Import/Export Contacts function in AR90A to update the tax statuses on Ship-to Address. In older versions, use Import/Export shipping addresses in OE.