Forum Moderators: buckworks
I have no idea about Canada but many states in the US (including mine) require sales tax to be charged on S&H or delivery charges as well as the physical items.
Unfortunately, I found this out the hard way (a random sales tax audit). Luckily, we didn't have that many in-state sales that were charged S&H at the time.
Your state/local sales tax authority can let you know what's required in your area.
"Apply sales tax to S&H" is standard optional setting in my chosen shopping cart software as well as our selling account on eBay.
If there is applicable local sales tax, the purchaser may be responsible (depends on the jusidiction) to submit sales taxes for internet purchases they make. Although I really do not think anybody does it. But make sure you put that in your terms on your site just to cover yourself.