Ever wondered about those USSD codes used by your mobile phone company?
USSD, or unstructured supplementary service data, allows mobile subscribers to communicate with their network for airtime balances, bundle purchases, Sim swaps and more, regardless of how sophisticated (or unsophisticated) their device happens to be.
When a user dials a USSD code – they start with a star and end in a hash – their request is routed to a special gateway. This gateway converts the request into the short message peer-to-peer (SMPP) format and it’s then routed to the appropriate server for a response.
Since USSD does not use data connectivity, no data charges are incurred by users (though other charges can apply). A connection to the mobile network is the only prerequisite for initiating a session, which is limited to three-minute intervals to avoid network congestion.
Telecommunications providers often zero-rate USSD sessions to make it easier for their subscribers to access their services. Third parties like banks can also use USSD to offer services to their customers via mobile without having to worry about the differences in capability between smartphones and feature phones.
Third-party USSD services may also be zero-rated or charged at a standard rate of 20c/20s. Some services charge premium rates, although this is rare. Even Android phone manufacturers offer an extensive array of short codes (particularly useful for support technicians or tech-savvy users), but that is not the subject of this article.
Unique codes
Each telecoms provider has a unique set of codes to offer access to its USSD services. TechCentral asked South Africa’s four mobile operators to provide the main USSD codes they have deployed on their networks. See the tables for MTN South Africa, Vodacom South Africa and Telkom below — Cell C had not responded to our inquiry by the time of publication.
MTN South Africa
| USSD code | Service |
| *135# | Customer self-service service: roaming, Rica status, mobile number portability, Sim swap, out-of-office settings, content management |
| *136# | Customer self-service service: balance enquiry, purchase airtime and bundles, menu redirects to other services (Made4U, MyMTN Gifts, 135 self-service) |
| *142# | Purchase Made4U bundles |
| *155# | Subscription management services: view/cancel subscriptions, change spend limits, opt out of third-party messages |
| *151# | MTN financial services: Mobile Money, XtraTime (airtime advance) |
| *120# and *130# ranges | Wasp services |
| *112# | Emergency services |
| *121# | Please call me menu |
Telkom
| USSD code | Service |
| *180#/*141#/*147#/*111#/*209# | Telkom Mobile account menu |
| *188#/*100#/*101#/*102#/*136# | Balance enquiry/recharge |
| *140# | Please call me menu |
| *123# | Mo’nice |
| *1# | MSISDN and IMSI inquiry |
| *2# | IMSI inquiry |
| *198*5# | Rica |
| *187# | Bring a Buddy campaign |
Vodacom South Africa
| USSD code | Service |
| *100# | Prepaid balance check |
| *117# | Welcome tones and content discovery |
| *120# | Wasp services |
| *135# | Customer care – self-service |
| *136# | Prepaid recharge |
| *140# | Please call me menu |
Most of the codes listed in these tables lead to menus where options can be selected using numerical options.
Completing a transaction via USSD may involve making a number of selections, each of which takes you to another menu until a final selection is made.
Once memorised, the “direct” code can be used instead to save time. For example, dialling *180*3*1*1# on the Telkom network buys the FlexOn 2GB bundle for R149.
Although this is faster, it is advisable to go via the on-screen menu options to avoid making incorrect purchases as the menus are changed from time to time. – © 2023 NewsCentral Media