People who don't live in areas immediately at risk of a bushfire threat may still receive emergency text alerts about the blaze and evacuation measures, fire authorities say.
The message from the ACT Emergency Services Agency comes as an out-of-control bushfire burns in the Namadgi National Park, which has already burnt more than 2500 hectares.
More than 15,000 emergency alert text messages were sent to Canberrans on Monday after the fire started and reached a watch and act alert level. The alerts targeted those living near the Namadgi National Park and southern suburbs in Tuggeranong.
Some people out of those areas also received the text message alerts.
ACT Emergency Services Agency commissioner Georgeina Whelan detailed the emergency message system on Tuesday morning.
"The emergency alert messaging system will send information to a mobile that has registered on a cell tower that is servicing the warning area," Ms Whelan said.
"If you live in an area or home serviced by the certain tower, or you may have also driven through the area, irrespective of whatever area you are in at time of the alert is issued, if you're in an area with no limitation to infrastructure, you will receive it."
Optus and Vodafone customers who had driven through the warning area in the 60 minutes before the emergency alert was issued would still receive the text messages, even if they were no longer in the area at the time of the alert, Ms Whelan said.
Telstra customers will receive the alert if they have driven through the alert zone between 50 and 74 minutes before the alert was issued.
Voice messages are also sent to landline phones.
However, Ms Whelan said residents in potentially affected areas may not receive alerts depending on their movements before the alert was issued, and urged Canberrans to continually check bushfire updates if they live in areas at risk.
"If you left your home this morning and went out more than 90 minutes before an alert was issued, you won't receive a text," Ms Whelan said.
"This is why you need to maintain visibility of the fire situation on other mediums."
Ms Whelan said it was important that people read and understood the message alerts.
Fire updates are issued by the ACT Emergency Services Agency every 30 minutes for fires at an emergency level, every two hours for fires at watch and act, or when the situation changed, and every 24 hours for fires at advice level.
While the NSW Rural Fire Service's Fires Near Me app and website has information and the location of ACT fires, Ms Whelan said the Emergency Services Agency's website provided more up-to-date information on ACT bushfires.
"Fires Near Me is administered by the NSW RFS and can carry a short delay as we transfer information from our incident control room to the website and across to NSW," she said.
After the ACT ESA's website went down for two hours last week during the bushfire that threatened Beard and Pialligo, Ms Whelan said she could not guarantee the website wouldn't be affected by a similar incident due to an outage.
"It is important that you don't rely on just one source of information," Ms Whelan said.
"Please actively seek information so you can make an informed decision when you need to."
The ACT remains in a state of alert, which was issued on January 2.
While the state of alert was rolled back on January 20 to only rural and remote areas of the ACT, it was reinstated for the entire territory on January 24 following a flare up of bushfire conditions.
The issuing of a state of alert for the ACT means the emergency services minister must give regular situation reports and an emergency controller appointed, a position held by Ms Whelan.
The controller has the power to direct people and prohibit people from entering an area as well as co-ordinate the distribution of emergency water, food and power.