EAS makes use of the cell broadcast service technology to disseminate messages for reception by compatible mobile devices simultaneously and within seconds. Similar systems have been deployed in the United States, Japan, Korea, etc. for dissemination of emergency messages by the governments.

No. EAS messages are broadcast to all mobile devices connected to mobile networks. Throughout the process, the EAS does not collect or store mobile phone numbers or any personal information of the mobile service users.

You are not required to pay any additional charge for the reception of EAS messages.

Upon receipt of an EAS message disseminated by a Government Bureau or Department, apart from a text message popped up on the screen, your mobile device will generate an audio alarm signal together with vibration for about ten seconds with a specific pattern / rhythm to alert you of reception of EAS message (for details, please refer to Q.6, Q.13 and Q.14).

When an EAS message is disseminated, the Government Bureau or Department disseminating the EAS message would also publish the relevant information on their official website or social media platforms. You may visit the relevant official website or social media platforms or contact the Government Bureau or Department concerned for further information.

No. Only mobile devices that support cell broadcast service technology with the cell broadcast feature enabled on the devices can receive EAS messages.

Please see a list  of the brands and model numbers of mobile devices that support cell broadcast service technology, as well as the corresponding software versions of these devices that enable the cell broadcast feature.

The list will be updated from time to time following mobile device suppliers' / manufacturers' launch of new models of mobile devices that support reception of EAS messages, or release of software updates for older models that enable the cell broadcast feature.

If the model of the mobile device that you are using does not appear on the list, or if you have any questions in relation to checking or updating the software version of your mobile device, please contact your mobile service provider or the relevant mobile device supplier / manufacturer for assistance.

Mobile devices enabled to receive EAS messages will generate an audio alarm signal together with vibration for about ten seconds to alert users of reception of an EAS message. Notification will also pop up on the screen.

No. Only mobile service users (including inbound roamers) located within the coverage of local mobile networks and with their devices connected to the networks can receive EAS messages disseminated through the networks.

Even if you and your friend use the same mobile device model, you may not receive EAS messages under any of the following circumstances:

• your mobile device is turned off or outside the coverage of the mobile network through which mobile services are provided to you when the EAS message is disseminated;
• your mobile device has been configured in such a way that the reception of EAS messages at "Emergency Alert" level has been opted out. Whilst you will be able to receive EAS messages at "Extreme Emergency Alert" level, you will need to reconfigure your mobile device in order to opt in reception of EAS messages at "Emergency Alert" level. Please refer to Q.11 on how to configure the reception of EAS messages; or
• your mobile device has not been installed with the version of software update that enables the cell broadcast feature. In such circumstances, you will need to install the relevant software version on your mobile device in order to receive EAS messages properly. Please check here  for a list of the brands and models of mobile devices that support cell broadcast service technology, as well as the corresponding software versions of these devices that enable the cell broadcast feature.

No. In order to receive EAS messages, your mobile device will need to connect to a 3G, 4G or 5G mobile network.

Mobile service users using mobile devices that are enabled with the cell broadcast feature will be able to receive EAS messages so long as their devices are connected to a local mobile network. Accordingly, not only customers of a mobile network operator are able to receive EAS messages, but also customers of mobile virtual network operators and mobile service resellers whose compatible mobile devices are connected to the same underlying mobile network. Likewise, overseas visitors roaming to a local mobile network will be able to receive EAS messages disseminated through that network so long as their mobile devices are enabled with the cell broadcast feature.

So long as the model of your mobile device falls within the list  and is installed with the relevant software version to enable the cell broadcast feature, you will be able to receive EAS messages without the need of doing any further configuration, as it is a default factory setting of new models of mobile devices or default setting in the software update for existing models of mobile devices to enable reception of EAS messages at both the "Extreme Emergency Alert" and "Emergency Alert" levels.

A mobile device enabled with cell broadcast feature cannot be configured to opt out reception of messages at "Extreme Emergency Alert", but messages at "Emergency Alert" level may be opted out. If you would want to check whether you mobile device has been configured (or reconfigured) to opt in (or opt out) reception of EAS messages at "Emergency Alert" level, you may refer to the list  and check the device settings information for your device model, as well as instructions on how to do the configuration as necessary. If you have any further questions in this regard, please contact your mobile service provider or the relevant mobile device supplier / manufacturer for assistance.

Members of the public are urged to maintain the configuration of their mobile devices for reception of EAS messages in order to receive Government information relating to personal safety in a timely manner.

"Extreme Emergency Alert" is the highest level of alert and messages at this level will only be sent in the most severe situation requiring immediate responses or actions by all of the affected citizens in Hong Kong to clear and present danger that could cause the loss of human lives, serious personal injuries and massive damage to property. It is therefore of utmost importance that mobile service users having compatible mobile devices will receive EAS messages at "Extreme Emergency Alert" level. In overseas jurisdictions where similar systems are deployed, mobile service users are also in general not able to opt out reception of messages at the highest level.

You are not able to mute or adjust the audio alarm signal or turn off the vibration alert of messages at "Extreme Emergency Alert" level. As to whether you can mute or adjust the audio alarm signal or turn off the vibration alert of messages at "Emergency Alert" level, it depends on the model of the mobile device you use.

The audio alarm signal and vibration alert are required to follow the pattern / rhythm as specified in the technical standard for reception of EAS messages and cannot be changed by users.

For mobile devices with cell broadcast feature enabled, it is a default factory setting to disable reception of EAS test messages. The test message mode is to enable the Government and the mobile network operators to conduct tests on the EAS from time to time. EAS messages which are expressly marked as "Test Message" may be sent at times to specific cell sites or on a regional / territory wide basis for testing purposes. If you happen to receive EAS test messages on your mobile device, please ignore them and you may reconfigure your device setting to opt out reception of EAS test messages.