Cellphone coverage is comparable to that of South Africa, with service available even in most nature reserves (although it might be weak). In Swaziland, there is just one cellular operator, MTN-Swazi. South African SIM cards will not function here unless they are MTN and roaming has been activated. Almost any petrol station or grocery shop will sell you a starting pack with an MTN-Swazi sim card. To obtain a pack, you don’t need evidence of residency or identification.
Although there is coverage, the phone service is poor, with many calls failing to connect (or connecting to the incorrect phone number), SMSes failing to arrive, and international calling costs more than in South Africa.
If you don’t use your Starter Pack sim card within 30 days, it will expire, and you won’t be able to use it in South Africa.