SUN MobileFlex-Mobile SIM Card

User Guide
This user guide provides you with details on how to use your Flex-Mobile SIM Card for local voice call, Mobile Data, value-added services, roaming voice services and roaming data service.

1. Customer Service Hotline
You can call our 24-hour hotline number 7288 3388 to:
•   Set your preferred language;
•   Check credit balance, expiry date & assigned mobile number enquiry;
•   Recharge your Flex-Mobile SIM Card; or
•   Contact customer services or report loss.

2. SUN Mobile Flex-Mobile account servicing website
Visit website at

After you have activated this service, you can divert all incoming calls to your designated local telephone number.
>> To activate:  
Press **21* Telephone Number 
>> To deactivate:     
Press ##21#
Or you can activate/deactivate this service via your handset menu.

No need to apply for the service nor require any deposit, you can make high quality IDD calls with your Prepaid SIM Card.

Make an IDD call:
Press 001 / 1718 + Country Code + Area Code + Telephone Number
• The IDD call will be charged once the call is connected.
• International operator assisted calls (e.g. collect call) is not applicable to this SIM Card.

With Flex-Mobile SIM Card roaming service, you can enjoy our roaming service to keep close contact with your friends and family. 

When you arrive at your overseas destination, most handsets will select a foreign network automatically after power-on. However, if your handset fails to do so, please refer to your handset manual and follow the steps for manual network selection. The overseas network operator’s name will be displayed on your handset screen after successful selection and you are ready to make or receive calls. If for any reasons, you cannot make calls, please try to restart your handset and redial.  If the foreign network operator you selected does not support this roaming service, please select another operator manually and redial.   The roaming destinations and roaming operators may change from time to time, please refer to for details.

You need to maintain a minimum credit balance of $12.5 in order to make or receive call overseas.


Hong Kong Telephone No.



After you arrive at roaming destination and successfully subscribe to data roaming service, just simply follow the guide below to set the correct APN name to ensure the roaming data service works properly.

For Always-On-Data Plans:
You can activate your data roaming package when you arrive at the destination by dialing the followings codes on your handset:


For Travel Easy Packages:
There is no need to enter any codes. Your data roaming service will automatically be activated once you insert in the Travel Easy SIM card into your handset.

You will receive a welcome SMS confirming activation of your data roaming service.

Set the APN name as “sunmobile”

Settings  >  Wireless & Network  >  More Settings  >  Mobile networks  >  Access Point Names  >  +New APN  >  APN  > Insert “sunmobile”

iPhone: Settings > Cellular > Cellular Data Network > APN: Insert “sunmobile”


When your credit is about to be used up or you want to extend the SIM Card’s validity period, you need to recharge your SIM Card by any of the following methods:

1. Recharge Voucher
You can buy a Recharge Voucher at any of our SUN Mobile shops and follow this procedure to recharge your SIM Card:
Dial 7288 3388 from your handset
[select language (if applicable)]
Press 1 to select “Recharge by Voucher”
Key in the activation number printed on the Recharge Voucher
You can listen to the new credit balance and expiry date.
Notes: The recharge value will be loaded into your SIM Card instantly.

2.  Recharge at SUN Mobile Shops
You may recharge your Flex-Mobile SIM Card for no more than $5,000 at any SUN Mobile shops in the following manner:
For recharge value less than $100, you may recharge by multiples of $20 or $50;
For recharge between $100 and $500, you may recharge by multiples of $100;
For recharge value over $500, you may recharge by multiples of $500.

If you have lost your SIM Card, please call 7288 3388 to report your loss immediately. You can bring your Cardholder Certificate to any SUN Mobile shops for SIM Card replacement. Your mobile phone number and credit balance at the time of reporting your loss will be retained and transferred to the new SIM Card. $100 service charge is required.

For any faulty Flex-Mobile SIM Card, please bring it along with your Cardholder Certificate to our shops and we will replace the SIM Card for you free of charge.

Should you have any problems in using this SIM Card, please visit our website, call our 24-hours hotline 7288 3388 or visit our SUN Mobile shops. We are always ready to serve you.


Featuring high speeds, coverage around Hong Kong, csl Wi-Fi Service connects to the Internet when you’re on the move.

Before you login to use csl Wi-Fi service, you need to:

How to login:

csl Wi-Fi service is provided by CSL Mobile Limited and Hong Kong Telecommunications (HKT) Limited subject to the terms and conditions of csl Wi-Fi service, available at  To know more about csl Wi-Fi hotspots and coverage, please visit