Q:Do you need to register for GST? A: you need to register for GST if you carry out a "taxable activity" and if your "turnover": 1. was over $60,000 for the last 12 months, or 2. is expected to go over $60,000 in the next 12 months, or 3. was less than $60,000 but GST is included in your price.like taxi driver who have to include 15% in their taxi fares. you can choose to voluntarily register for GST enve if your annual turnover is less than $60,000.