Last updated: August 2026
Data SIM deals provide a SIM with a data allocation and no voice minutes. They are the standard option for tablets, routers, dongles and second devices, and they are usually cheaper per gigabyte than adding data to a voice plan.
The main thing to establish first is which device the SIM is going into, because that determines both the allocation you need and the plan type that fits.
What a data SIM suits
| Device | Why a data SIM fits | Compare |
|---|---|---|
| Tablet | Connectivity away from WiFi without tethering | Data contract deals |
| LTE or 5G router | Household internet where fibre is unavailable | Router SIM deals |
| Dongle or MiFi | Portable connectivity for a laptop | LTE router deals |
| Second phone | Data-only line, with calls over internet services | SIM only deals |
Only cellular tablets can take a SIM. Wi-Fi-only models cannot, which catches people out reasonably often.
Sizing the allocation
Data SIMs are usually bought on the assumption of lighter use than a primary phone, but that is not always right. A router serving a household needs considerably more than a tablet used for reading on a commute.
- Tablet, light use. Browsing, email and messaging consume relatively little.
- Tablet, video. Streaming dominates. This is where allocations disappear.
- Router, household. Treat it as a home internet decision rather than a data SIM decision. See home internet deals.
The how much data do I need guide helps size it properly.
Compare by network
Compare by network
| Provider | What to check |
|---|---|
| Telkom | Often the strongest data pricing. See Telkom data deals. |
| MTN | Own network coverage. See MTN data deals. |
| Vodacom | Widest coverage. See Vodacom data deals. |
| Cell C | Competitive pricing. See Cell C data deals. |
Coverage matters at the location where the device is used, which for a router is a fixed address and for a tablet may be several places.
Compare by budget
Compare by budget
- Check the peak and off-peak split. Large allocations weighted overnight are less useful than they look.
- Confirm rollover. Some providers carry unused data forward, others do not.
- Watch out-of-bundle rates and whether they can be capped.
- Compare against SIM-only if you also need minutes.
Lower tiers sit on data deals under R100 and data deals under R200, with the broader picture on cheap data deals.
Before you apply
- Device compatibility — unlocked, and supporting the network’s bands.
- SIM size or eSIM support on the device.
- RICA — proof of identity and address required.
- Credit and affordability on contract plans, though the threshold is lower than for handset contracts.
See apply for a data contract, or the wider market on best contract deals South Africa.
Frequently asked questions
Can I use a data SIM in a phone?
Yes, but there are no voice minutes, so calls would need to go over an internet-based service.
Will a data SIM work in any tablet?
Only in cellular models. Wi-Fi-only tablets have no SIM slot and cannot take one.
Is a data SIM cheaper than prepaid data?
Usually cheaper per gigabyte, but it commits you for the contract term. Prepaid is more flexible and costs more per gigabyte.
Does unused data roll over?
It varies by provider and plan. Confirm before choosing.
Can I move the SIM between devices?
Generally yes for standard data SIMs, though some home router packages are locked to a registered address. Confirm the terms.
More comparisons
- Data SIM Vs SIM Only
- SIM Only Deals Under R100
- Online Cellphone Contracts
- Cheap Data SIM Deals
- MTN 5G Home Internet
- Vodacom 5G Home Internet
- Cheap SIM Only Deals South Africa
- Contract Deals
- Do Cellphone Contracts Check Credit Score?
Pricing, availability, bundle structures, coverage and approval criteria change regularly and are set by the provider. Confirm all current terms directly with the network before applying.