According to the Inland Revenue Department (IRD), anyone who performs a taxable activity and has an annual turnover of more than $60,000 should register for GST. A taxable activity means anything carried out regularly by a business, manufacturer, professional or association. Generally, the annual turnover refers to the total sales and income made in a year.
A GST-registered enterprise collects GST on behalf of the Government by adding it into the prices of their products and services. They claim GST back on the products or services they have bought as business expenses.
In your case, failing to register for GST will not only lead to certain penalties, it can also rob you off some benefits.