In the tax configuration, there's an option to apply taxes to shipping & handling. As far as I can tell, this only kicks in if the product ALSO has a sales tax. From the popup helper:
"If checked, then when this tax applies to a product, it will also be collected on the amount charged for shipping and handling."
How do I charge sales tax (and show the tax amount) on shipping for a tax-exempt product? Most of my products are "zero-rated" for sales tax but GST should be charged for shipping.