Before Travel

Well-prepared before travelling and stay connected with family and friends. Customers can activate the roaming service and subscribe roaming data or voice packages before travelling.

Roaming Service Setting

Customers should turn on the roaming service function at their mobile account if roaming service is needed. To use roaming voice and data service, “International Roaming – Voice & Data” should be turned on. To use roaming voice service only, “International Roaming - Voice only” should be turned on.

Below are the roaming service activation and deactivation methods:

Roaming Service Activate/ Deactivate USSD Code  MyLink
Activate International Roaming – Voice & Data
(Able to use Voice & Data Roaming Service in worldwide)
(1) Login account
(2) Select “Telecom” > “My account” 
(3) Go to “My Roaming Service” or “My VAS Service” to check if related services are activated
If the roaming service has not been activated, please go to “My Roaming Service” > “Available VAS” or “My VAS Service” > “Subscribe More” to activate the service
Activate International Roaming - Voice only
(Able to use Voice Roaming Service only in worldwide, not include Data Roaming Service)
De-activate All International Roaming – Voice & Data
(Voice and data roaming cannot be used after deactivation)

(Once deactivated, the service cannot be activated overseas with USSD code)

Follow (1) to (3), deactivate the “International Roaming – Voice only” or “International Roaming – Voice & Data” in “My Roaming Service” > “Current VAS” or “My VAS Service”.
  • Customer must enable local data service (Press *106*01#) first before activate the roaming data service
  • Since part of the roaming operators do not support short code, suggest to activate or de-activate the International Roaming Service by pressing USSD code before leaving Hong Kong when necessary.


Voice Roaming Preparation

  • All CMHK customers can use Roaming Call Back Service directly without application or any deposit.
  • In addition, you can also choose to apply CMHK's IDD Service, and make IDD calls to other countries/destinations when you are roaming abroad: Simply visit any conveniently located CMHK Shops or Customer Care Centre to register, and pay a refundable IDD deposit of HK$1,000, or register to settle your bill through direct debit from your credit card. One day to activate. All subscribers who have paid an IDD001 deposit can enjoy IDD Service while roaming without further registration.
  • Remember to cancel 「No Answer Call Forwarding」, 「Unreachable Call Forwarding」, or 「Busy Call Forwarding」before departure, or press to cancel all call forwarding services, in order to avoid unnecessary roaming charges caused by call forwarding.


Usage Control Tips

All mobile data roaming usages generated via mobile devices (including handsets and mobile dongles, and connecting for tethering) will be subject to data roaming charges. These data usages may include WAP and Web browsing, sending and Receiving MMS, using Instant Messaging (e.g. Whatsapp, Wechat), navigation service (e.g. Google Map), using Internet Gaming etc.


To effectively control data roaming usages and related charges, you may consider adopting the following measures according to your needs:
  • If data roaming service is not needed when travelling abroad, we suggest you deactivate data service (reserve roaming voice service) by pressing           on your handset before departing Hong Kong to avoid unnecessary charge. Please note data charge may still be incurred even if you have turned off data roaming service on your handset.
  • Double check that mobile data function remains switched off whenever you re-start your handset
  • Check your data usage regularly -- by using your handset’s counter function, entering relevant short code  (         ) on your handset, or by logging onto CMHK website
  • Check frequently that, while using Wi-Fi to access Internet, your handset has not switched connection using mobile data services
  • Switch off the auto update / push email / push notification / location update functions of your handset or mobile apps if they are not needed
  • Try to browse the “mobile version” instead of full version of websites (e.g. Facebook / Yahoo!) in order to minimise the data usages


Don't do the following unless you really need to use the services, understand the nature of such usages, and know the expected data volume to be incurred:
  • Open email attachments
  • Visit websites which may incur high volume of data transfer (e.g. YouTube)
  • Use mobile apps which may incur data usages
  • Use instant messaging applications which may check your status automatically
  • Use services which may incur high volume of data transmission, e.g. File transfer or music downloads
  • Use applications which may incur unexpected or unknown volume of data transfer, e.g. Software or hardware updates / bit torrent / video streaming / mapping service (ie. Google Maps) / AGPS location update (i.e. use Geotagging in photo shooting)


Check/Apply Roaming Products

 Apply Roaming Products

Seamless communications around the world! CMHK's International Roaming Service reaches to more than 300 roaming destinations and over 600 roaming partners. You may login MyLink – International Roaming page or click here to check for more data roaming products or here to check for more voice roaming products. You may also click here to apply the roaming products.
You may click here to check current roaming VAS.