If you sell more than $30,000 of taxable goods or services annually, the Canada Revenue Agency requires you to register for a GST/HST account. You can register for an account even if your revenue is lower than the threshold. Once registered, you must determine which of your goods or services are taxable and then charge your customers tax accordingly depending on the sales tax rate in your province. For example, in New Brunswick, harmonized sales tax is 15 percent, meaning you charge $15 in tax on a $100 purchase. Invoice templates or software can help you calculate GST/HST.
Depending on the volume of business you do, the CRA will send you a personalized GST/HST return monthly, quarterly or annually. As you collect sales tax, deposit the funds in a separate account, and remit the sales tax to the CRA using the funds you have set aside.