In Canada it seems to depend on whether they try to charge duty on the item. If they need to collect money at the door, there are added handling fees. I was aware of the handling fee and the tax, but was incorrectly charged duty as well which seemed to trigger the extra handling fee. Bike parts in Canada are duty free, but someone at the border incorrectly labelled my parts as 'bikes - other' which includes duty, instead of 'bike parts - other' which is duty free. Here at least they have a refund procedure for incorrectly classified items to get the duty/taxes back, but the handling fee is on the Canada Post side.