What a fixed IP SIM card does
A normal mobile data SIM shares one public address with thousands of other users. The network hides your device behind carrier-grade NAT, so the device can reach the internet but nothing on the internet can reach the device. That is fine for a phone. It is a problem for a CCTV recorder you need to view, a PLC you need to program or a router you need to manage.
A fixed IP SIM card solves this. Each SIM is given its own static IP address that never changes. With a fixed public IP the device is reachable directly over the internet, so port forwarding, remote desktop and site-to-site VPNs just work. With a fixed private IP the device sits on a private mobile network and you reach it over a secure VPN, with no exposure to the public internet at all.
Choose the right SIM for the job
Every SIM type below is available with a fixed public IP, a fixed private IP or a dynamic IP. The difference is how the SIM chooses and uses networks.
| SIM type | Networks it can use | Best for |
|---|---|---|
| Multi network SIM | EE, O2, Vodafone and Three from one SIM, switching when coverage fails | Unmanned sites, unknown coverage, anything that must stay online |
| Multi-IMSI SIM | Several network identities held on one SIM, selected by an applet or over the air | Long life IoT, international estates, avoiding permanent roaming limits |
| Roaming SIM | All four UK networks plus partner networks in Europe and beyond | Vehicles, plant hire, equipment that crosses borders |
| Single network SIM | One network: EE, O2, Vodafone or Three | Fixed sites with a proven strong signal, or a second SIM in a dual SIM router |
| IoT SIM | Any of the above, with tariffs sized for low data devices | Meters, sensors, alarms, telemetry and trackers |
| eSIM | Network profiles downloaded to an embedded SIM | Sealed devices and large rollouts that must change network remotely |
The UK mobile networks in 2026
There are now three mobile network groups in the UK, not four. Knowing who owns which masts matters when you are buying for resilience.
- EEOwned by BT Group. Widest 4G footprint and a large business and IoT customer base.
- O2Run by Virgin Media O2. Strong in towns and cities and long established in IoT and smart metering.
- Vodafone and ThreeNow one company, VodafoneThree. Both brands continue, but since 2026 they share radio sites and core network, so either SIM can use either set of masts.
For a genuinely resilient site, pair networks from different groups: EE with O2, or either of those with VodafoneThree. What the Vodafone and Three merger means for your SIMs
Where our SIM cards are used
- CCTV and security
- View NVRs and cameras on building sites, car parks and remote compounds without a fixed line.
- Telemetry and SCADA
- Poll PLCs, RTUs and flow meters over Modbus TCP, DNP3 or MQTT at water, gas and energy sites.
- Energy and EV charging
- Manage battery storage, solar inverters and chargepoints from a central platform.
- Retail and payments
- Keep tills and card terminals trading on a private network when the broadband fails.
- Digital signage and kiosks
- Push content and fix screens remotely across hundreds of locations.
- Transport and fleets
- Connect onboard routers, cameras and passenger Wi-Fi as vehicles move between networks.
- Lifts, alarms and building systems
- Replace copper lines and old 2G and 3G modules with 4G connections that can be tested remotely.
- Temporary sites and events
- Stand up a network in hours for site cabins, pop-ups, film crews and festivals.
Routers and antennas, configured with your SIM
A fixed IP SIM is only as good as the router it sits in and the signal it receives. We supply 4G and 5G routers from Teltonika, ProRoute and Robustel, and indoor and outdoor antennas matched to each site.
Millbeck Communications is a Teltonika Diamond Partner. We can set up the firewall, port forwards and VPN before the router leaves us, so it works when it is plugged in.
Why buy from us
Fixed IP SIM is run by Millbeck Communications, a UK connectivity business in Leeds. Our team has worked with cellular routers and M2M data since the early days of 3G. We sell SIMs, routers and antennas together, so one team answers for the whole connection: which network, which IP option, which router settings and which antenna.
We quote every requirement individually. Tell us how many SIMs, how much data and what the devices do, and we will recommend the simplest setup that meets it.
Tell us what you need to connect
Questions we are often asked
What is a fixed IP SIM card?
A data SIM that is given the same IP address every time it connects to the mobile network. It lets you reach a router or device directly, which a standard SIM behind carrier-grade NAT does not allow.
Do I need a public or a private fixed IP?
Choose public if you want to reach the device from any internet connection, for example with a CCTV app or remote desktop, and you will protect it with a firewall. Choose private if the device must never be exposed to the internet and you are happy to connect over a VPN.
Can a fixed IP SIM use more than one network?
Yes. Our multi network and roaming SIMs can use EE, O2, Vodafone and Three and keep the same fixed IP address whichever network they are on.
Do fixed IP SIMs work with 5G routers?
Yes. Our SIMs work in 4G and 5G routers. Where 5G is available on the chosen network, a 5G router will use it with the same fixed IP address.
How are fixed IP SIM cards priced?
We quote each requirement based on the number of SIMs, the data allowance, the network option and the contract term. Send an enquiry and we will reply with a written quote.
Will my SIM still work after the 3G switch off?
Yes. All our SIMs work on 4G and 5G. The UK networks have now switched off 3G, so any device that relies on 3G needs a 4G or 5G modem. We can advise on replacement routers.