A GST/HST registrant must collect and remit GST/HST on sales of taxable supplies. The Excise Tax Act provides three classifications for supplies; fully taxable supplies, zero-rated supplies, and exempt supplies. How a supply is classified will determine to what extent a registrant must collect GST/HST, and what input tax credits (ITCs) and refunds that supplier may otherwise be entitled to. Classifying a supply depends on its nature and the scheduled lists of the Excise Tax Act itself. The distinction between expenses as fully taxable, zero-rated or exempt is complicated and essential for most any business engaging in commercial activity. If you are unsure how to classify a particular expense or what GST/HST benefits might be available for your business, then you should contact an expert Canadian tax lawyer.