Last updated: August 2026
A data SIM gives you data with no voice minutes. A SIM only plan gives you data plus minutes and SMS. That is the whole difference, and it means the right choice is decided by the device rather than by price.
Direct comparison
| Data SIM | SIM only | |
|---|---|---|
| Data | Yes | Yes |
| Voice minutes | No | Yes |
| SMS | Usually not | Yes |
| Cost per gigabyte | Often lower | Slightly higher — you are also buying minutes |
| Suits | Tablets, routers, dongles, second devices | A primary phone |
Choose by device
- Tablet — data SIM. You are not making conventional calls from it.
- Router — data SIM. Voice minutes would be wasted entirely. See router SIM deals.
- Primary phone — SIM only. Even if you mostly use WhatsApp, conventional calls still matter for banks, businesses and emergencies.
- Second phone — either, depending on whether it needs to receive normal calls.
The trap on a phone
A data SIM will work in a phone, and the lower per-gigabyte cost makes it tempting. The problem is what you lose: you cannot receive an ordinary call, which matters more than people anticipate.
Banks, delivery drivers, employers and emergency services use conventional calls. Internet-based calling covers most personal contact but not those. For a main line, the saving rarely justifies the gap.
Where to compare
For data SIMs see data SIM deals and data contract deals. For phone plans see SIM only deals and cheap SIM only deals.
For household connectivity a router package is usually better value than either — see home internet deals and LTE deals. See also SIM only vs phone contract and how much data do I need.
Frequently asked questions
Can I use a data SIM in a phone?
Yes, but there are no voice minutes, so you cannot make or receive ordinary calls.
Is a data SIM cheaper?
Often lower per gigabyte, since you are not paying for minutes. Whether it suits you depends on the device.
Do data SIMs need RICA?
Yes. Every SIM in South Africa requires registration. See RICA requirements.
Which do I need for a tablet?
A data SIM, and the tablet must be a cellular model rather than Wi-Fi only.
More comparisons
- Cellphone Contract Guides
- Cheap Data SIM Deals
- Phone And Data Bundle Deals
- Cell C Contract Deals
- Apply For Vodacom Contract
- Contract Deals
Pricing, availability and bundle structures are set by each provider and change regularly.