You have to register for the GST/HST if your sales of taxable goods or services during the fiscal period of your business exceeds $30,000. You must register and begin charging the GST/HST the month after you reach the $30,000 threshold. You cannot wait until the following year to register.
If you sell what is referred to as exempt goods and services such as dental services or music lessons, you don't need to register at all.
