Service introduction

KingKing is a complimentary service(3) for all 1O1O users

KingKing(1)(2)(4)(5)(6) from 1O1O is a VoIP application, based on Wi-Fi or mobile network connectivity that can be used in Hong Kong or while overseas. It offers FREE(3) voice minutes for making outgoing calls to any Hong Kong number and receiving incoming calls from anywhere in the world. Above all, KingKing will save you from running up huge voice roaming bills.

What KingKing can do for you:

  • You can make/receive calls, regardless of whether the called person is on a fixed-line or mobile phone. The person you call, or who calls you, does not have to be a 1O1O subscriber nor install any application. You can also send SMS(8) to anyone, regardless of their service provider.
  • You can use your existing 1O1O number and have your caller ID displayed to people you call, and see the ID of those calling you.


Use KingKing in Hong Kong

You can now use the full KingKing service via Wi-Fi or mobile network connectivity here while in Hong Kong. This enables you to familiarise yourself with the user interface and app features before making a trip. Download NOW to enjoy the kingly convenience of KingKing!

If you need technical assistance, simply call our 24-hour Customer ServiceHotline on 2888 1010.


Qualified customers

Starting from 11 March, 2024, the use of KingKing will only be applicable to customers on designated service plans, including but not limited to the following service plans*:

  • Any 1O1O 5G Prestige Service Plan
  • 1O1O Annual Plan

*If you have already subscribed to any 1O1O service plan on or before 10 March, 2024, you can continue using the KingKing service until further notice.



Service included Making outgoing voice calls to
non-HK phone numbers
Sending SMS
  • Make outgoing voice calls to Hong Kong phone numbers for free
  • Receive incoming voice calls from anywhere in the world for free
IDD charges SMS charge*

* Sending SMS via KingKing while overseas incurs a charge, as if you were in Hong Kong. This will save you significant roaming costs and the charge will be calculated based on the SMS service (including intra/inter-network and international arrangement) provided by us, as if you were in Hong Kong. KingKing does not facilitate receipt of SMS.


Applications download

Download(7) the KingKing app for FREE
Click on the icon to go to the KingKing app download platform


How to login

How to login and use "KingKing"
Select KingKing application icon on your handset menu; and

  1. Enter and submit your 1O1O mobile number and 1O1O “My Account” password when using KingKing (pic-1).
  2. Enter the four-digit one-time password (pic-2) sent to your mobile number by SMS.
  3. Accept the Terms & Conditions of KingKing (pic-3).
  4. Switch on KingKing so the icon on top left turns green, showing that all incoming and outgoing calls are connected via KingKing (pic-4).
  5. If you need technical assistance, simply call our 24-hour Customer Service Hotline on 2888 1010.
(Pic 1) (Pic 2) (Pic 3) (Pic 4)


"KingKing" settings and user guide for iPhone


"KingKing" settings and user guide for Android



Terms and Conditions for KingKing voice roaming service

  1. KingKing voice roaming service (“KK SERVICE”) is available only to CSL Mobile Limited subscribers and provided according to the terms & conditions governing your mobile service contract and special conditions for KK SERVICE.
  2. KK SERVICE is compatible only with certain handsets. CSL Mobile Limited cannot guarantee KK Service performance in respect of incompatible handset models, nor call quality at every single Wi-Fi hotspot or any other place where Wi-Fi/mobile data service is available.
  3. IDD charges will apply if making calls to non-Hong Kong phone numbers. And local voice call minutes will be deducted/charged for the duration of such a call. Any charges for Wi-Fi connectivity, mobile data, IDD and or international roaming are additional. All mobile data usage of the service will be deducted from your monthly data entitlement or charged onto your account accordingly. Charges apply if you use KK SERVICE to send SMS and are calculated based on the SMS service (including intra-network, inter-network and international arrangements) provided by us, as if you were in Hong Kong.
  4. Customers using KK SERVICE should download the latest KK SERVICE app to a mobile phone running iOS 13.0 or newer, or Android 9.0 or newer.
  5. KK SERVICE can be used to make emergency calls or send emergency SMS messages (only if registered for emergency SMS service) in Hong Kong, but cannot be used to make emergency calls or send emergency SMS to a local emergency centre when outside Hong Kong.
  6. When you utilise KK SERVICE, we will use your 1O1O mobile number to verify your eligibility for KK SERVICE and for purposes of KK SERVICE billing via your account at CSL Mobile Limited.
  7. Downloading the KK SERVICE app from the App Store or Google Play will incur a local mobile data charge, or roaming data charges if overseas.
  8. The KK SERVICE SMS feature cannot be used for receiving SMS.
  9. If you are using a device with more than one SIM slot, please note KK SERVICE is compatible only with using a SIM card in the primary SIM slot and is not compatible with eSIM.
  10. KK SERVICE needs a Wi-Fi or mobile data connection. It’s best to use Wi-Fi rather than mobile data. If you do not have Wi-Fi, using KK SERVICE may consume your mobile data entitlement and incur mobile data charges. Roaming data charges will be incurred when using KK SERVICE in certain ways overseas. Customers are required to pay such charges. For data charge details, please go to .
  11. 1O1O’s General Terms & Conditions apply ( to the relationship between 1O1O and yourself, in respect of your mobile service and KK SERVICE.
  12. CSL Mobile Limited may change these Terms & Conditions at any time without notice. All matters and disputes will be subject to CSL Mobile Limited’s final determination.