Civil Defence has tested a New Zealand wide emergency system.
The test of the new emergency alert system was carried out 6pm and 7pm on Sunday evening.
A message was received by mobile phones that were switched on, within the target area, and capable of receiving it. That was around a third of all phones.
The message sends automatically and people do not need to sign up or download any app to receive it.
Those wanting to know whether their phone can receive the message can check online.
Civil Defence said it expected the number of phones capable of receiving the message to increase over time as people replaced their phones with newer models.
The system had been developed as an additional channel to alert people when their life, health or property may be under threat in emergencies, the agency said.