When your work is conducted in New Zealand but your business primarily involves exporting goods and services to overseas clients, your products do not incur a GST charge (these are taxed at 0% GST, or are "zero-rated").
Zero-rated supplies still need to be declared on GST returns, but you won't incur a charge.
Invoices sent to Clients based overseas will display 'Hnry Limited' rather than your own name – this is required, otherwise payments will bounce. Although rest assured: your unique Hnry Bank Account is still listed on your Invoices so payments will still be processed as usual.
Note: if you work for an international client with offices in multiple countries (such as a recruiter), check with your client to see if you need to declare zero-rated GST.
If you don't primarily export your goods or services then zero-rated GST isn't something you need to worry about.