Account whitelisting is required.
Due to strict operator regulations, termination of all SMS towards New Zealand is considered best-effort delivery. This implies messages may or may not deliver. This is not under our control.
As a solution, you can procure a dedicated Short Code in New Zealand. This will be the most reliable alternative to deliver messages towards New Zealand, irrespective of the network operator. If you are interested in a 1-way or 2-way New Zealand-dedicated Short Code, please reach out to our Support Team for pricing and lead time.