About five million phones across New Zealand will receive an Emergency Mobile Alert when the system is tested on Sunday night.
NZ Civil Defence will test the system between 6-7pm on May 26.
"In a real-life emergency situation, an alert may be sent to target areas affected by serious hazards," NZ Civil Defence said.
"If you get an alert, stop, read the message, and take it seriously.
"It will tell you what the emergency is and what to do.
"It will also tell you which agency sent the message and if needed, where to go for more information."
The alert will be broadcast to all capable phones from targeted cell towers.
If your phone is on, capable, and its software is up to date you should receive the alert.
NZ Civil Defence said the alerts are not meant to replace other emergency alerts or the need to take action after natural warnings.
"Don't wait for an official warning if you feel your life is in danger. Take immediate action."
- Learn more about the Emergency Mobile Alerts system here.
