Canadian Dropshippers on Sales Tax

Are there any Canadian dropshippers out there selling on Amazon or Ebay making more than 30K gross that have some experience or knowledge if you need to register for a GST/HST account when you're not collecting sales tax on your sales?

Thanks so much.

If there isn't, I would suggest just contacting your local authority. They'll be able to clue you in with the requirements, unfortunately I'm completely clueless on this one.