When do I need to register for GST/HST?
Once your revenue exceeds $30,000 over four consecutive calendar quarters, registration becomes mandatory. You can register voluntarily earlier if you want to claim input tax credits.
Do I need a Business Number if I'm a sole proprietor?
A BN isn't automatically required for a basic sole proprietorship, but you'll need one as soon as you register for GST/HST, payroll, or incorporate.
How much should I set aside for taxes?
25-30% of every payment is a safe starting estimate for most small businesses, though your actual rate depends on your income level, province, and structure.
Is this checklist different in the US?
Yes — see the US version of this checklist, which covers EIN registration and state-level sales tax instead of CRA and GST/HST.