The right SIM type depends on whether your device needs to be reachable from outside. Dynamic IP SIMs (from £2.20/month) suit devices that only send data out – routers providing general internet access, trackers, sensors. Private IP with VPN SIMs (also from £2.20/month) suit devices you need to remotely access securely – routers, CCTV, SCADA. Fixed public IP SIMs (from £12.00/month) suit setups where a third-party system needs to connect directly to your device’s address.
The question that decides everything
Before looking at data allowances, pricing or hardware, there’s one question that determines which SIM type you need: does anything outside your device need to connect into it?
If the answer is no – your device sends data to a server, platform or app, and that’s the whole relationship – you need a dynamic IP roaming SIM. This covers most sensors, trackers, vending machines and routers that simply provide internet access to a site.
If the answer is yes – you (or a system you manage) need to log into the device, view its cameras, access its configuration, or connect to equipment on its network – you need either a private IP SIM with VPN or a fixed public IP SIM.
Private IP with VPN, or fixed public IP?
Both of these options allow inbound access, but they work differently and have different security implications.
| Private IP + VPN | Fixed Public IP | |
|---|---|---|
| Visible to internet scanning? | No | Yes |
| Access method | VPN tunnel (IPsec, OpenVPN, WireGuard) | Direct connection to public IP |
| Typical use case | Remote management, CCTV viewing, SCADA | Third-party systems needing direct IP access |
| From | £2.20/month | £12.00/month |
For most customers wanting to remotely manage routers, view CCTV or access SCADA equipment, private IP with VPN is the option we’d suggest looking at first – the device simply isn’t visible on the public internet, which removes an entire category of risk. Fixed public IP remains the right tool when a specific integration genuinely requires a direct address, and in those cases we’d recommend pairing it with the hardening steps in our router security guide.
Worked examples
- A 4G router providing site internet access, no remote login needed → Dynamic IP
- A vehicle tracker reporting location to a platform → Dynamic IP
- A router you need to log into remotely to check status or change settings → Private IP + VPN
- A CCTV recorder you want to view footage from remotely → Private IP + VPN
- SCADA equipment a third-party monitoring platform connects to directly by IP → Fixed Public IP (with hardening)
Still not sure? Get in touch with a quick description of your device and how it needs to be used, and we’ll recommend the right SIM type.