Australia has adopted the new National Terrorism Threat Advisory System (NTTAS), which replaces the former National Terrorism Threat System and the Public Alert System.
The new system is comprised of five levels to indicate the national terrorism threat level:
- Not expected (green)
- Possible (blue)
- Probable (yellow)
- Expected (orange)
- Certain (red)
Under the system Australia is at a probable level of threat. The probable level advised that members of the public should go about their daily routine and exercise caution and report any suspicious incidents to the National Security Hotline on 1800 1234 00.
Any change to the National Terrorism Threat Level will be announced by the federal government.
National Terrorism Threat Level
The National Terrorism Threat Level is a scale of five levels (see diagram below) that tells the public about the likelihood of an act of terrorism occurring in Australia. Whenever the Government makes a change to the National Terrorism Threat Level it will explain why there is a change. The National Terrorism Threat Advisory System will inform Australians about the likelihood of an act of terrorism occurring in Australia and enable authorities, businesses and individuals to take appropriate measures for their own safety and security as well as that of their family, friends and associates.
The National Terrorism Threat Level also provides an indicator to government agencies enabling them to respond appropriately with national threat preparedness and response planning. This ensures that an appropriate level of precaution and vigilance is maintained to minimise the threat of a terrorist incident.
The Australian Government regularly reviews the security environment and the Threat Level.
The Australian Government has introduced a new National Terrorism Threat Advisory System. The System:
- comprises a five tier, colour coded, National Terrorism Threat scale to inform the public about the level of the terrorist threat facing the nation
- includes public advice on the nature of the threat we face and what it means for them
- will help inform the public so they can decide on what measures they can take to protect themselves, families and friends
- guides national preparation and planning to protect against the threat of a terrorist incident
- rebalances the threat levels to reflect the current security environment that the country is facing
A change to the National Terrorism Threat Level will be announced by the Prime Minister, the Minister Assisting the Prime Minister on Counter-Terrorism, the Director- General of ASIO, or the Counter-Terrorism Coordinator. Information about the new system and the current level can be found at
Reporting suspicious activity
The National Security Hotline is the single point of contact for the public to report possible signs of terrorism. Every piece of information is treated seriously, as it could be vital in preventing a terrorist act. The hotline also provides information to callers on a wide range of national security matters.
Reviewed 04 June 2021