New regulations that came into affect yesterday have made it compulsory for senders of commercial SMS spam to offer an option for stopping them with a reply SMS.

News24 reports that the regulations stipulate that consumers must have the means of opting out from receiving unsolicited commercial SMSs from within South Africa by replying with the word "stop" from their phone.
It says that the regulation has been introduced by the Wireless Application Service Providers Association (Waspa) and accepted by the South African SMS-messaging industry.
The "stop" SMS option must appear at the top of the SMS and it may not cost more than a standard SMS, or an alternative option must be provided. Using the "stop" function, users will be able to stop unwanted SMSs and have their numbers removed from databases.