Amazon collected the sales tax on my orders, is that my GST to remit

When a marketplace collects the sales tax on your order and remits it itself, that tax is not yours to remit again, and it was never your revenue either. It passed through you.

Under Canada's rules for digital-economy and marketplace sales, a platform can be treated as the supplier for sales it facilitates, which makes the platform responsible for charging, collecting and remitting the GST/HST on those orders. Where that applies, the tax never belongs to you at any point.

The trap is in the bookkeeping. A payout report shows a tax figure, so it's easy to record it as tax you collected, which inflates your revenue and, worse, makes it look like you owe the government money a marketplace has already paid. Left alone, that overstates your net tax and you can end up remitting it twice.

How to treat it

• Platform-collected, platform-remitted tax is pass-through: not revenue, and not part of the GST/HST you report as collected
• Tax you charged and collected on your own storefront sales is yours, and does belong on your return
• Keep the two separate in your books, because a single payout can contain both

Where it gets specific to you

Whether a marketplace collected on your behalf depends on things like your own registration status and how that platform treats its sellers: the rules turn on whether the vendor is registered. Your marketplace's tax documentation states what it collected and remitted for you; that plus your accountant's read of your registration is what settles it. We can show you the numbers cleanly; the call on your specific situation is theirs.