How much time will it take to make my business compliant with this regulation?

Registration is fairly simple. You can obtain IRD number by logging into Inland Revenue website and following the registration process. Allow sufficient time to ensure your business website is capable of capturing GST payment at the point of sale and that the tax is invoiced to the end consumer accordingly. You will also need to provide the details as noted in Q4 to Aramex / Fastway for all shipments of low value arriving in New Zealand on or after 1 December 2019.