What used to be a reliable, cost-effective way to connect remote devices is now becoming a hidden liability. Fixed IP SIM cards with public IP addresses were once the industry standard for remote access to Building Management Systems (BMS), CCTV cameras, and other IoT infrastructure. But today, if you’re still using them without extra protections, you could be:
In this guide, we’ll break down exactly why your data usage might be surging, explain the security vulnerabilities tied to fixed public IP SIMs, and show you how to diagnose, fix, and future-proof your setup.
TL;DR: If you’re using a SIM card with a public IP and port forwarding to access your device remotely, it could be under constant attack or automated scanning. There are better, safer ways to do this now.
A Fixed IP SIM is a mobile data SIM that assigns a static IP address to the connected device. When it has a public IP address, it can be accessed from anywhere on the internet without VPNs or complex network routing.
This was (and still is) appealing for use cases like:
The benefit? No setup required. Just insert the SIM, forward the relevant ports, and you’re live.
But there’s a dark side to that simplicity.
Using public IP SIMs with open ports was seen as low-risk. Attacks were rare, internet bots were relatively primitive, and most systems weren’t on anyone’s radar.
Everything has changed:
In short: if your device is online, it will be found.
Let’s take a common example: a BMS system with a basic login page exposed to the internet.
Each page load includes:
Scenario: Bots or scanners discover the page and hit it once every 10 seconds.
Calculation:
135KB × 6/min × 60/hr × 24/day = 1.1GB/dayNow imagine just 2 or 3 bots doing this simultaneously, or hitting multiple endpoints like /admin, /config, /api/status.
Result: You can hit 10–15GB of data use in a month without a single legitimate user logging in.
That’s not just inconvenient. If you’re paying £7.50 per GB over a 1GB plan, you’re looking at an extra £60–£100/month per site.
Many mainstream providers still offer fixed public IP SIM cards. While they serve a purpose, they must be used with caution. Some of the most common include:
Again, these providers aren’t doing anything wrong — but the market has shifted, and leaving devices directly exposed via public IP is no longer safe or sustainable.
These are common and understandable responses. But the danger here isn’t dramatic — it’s silent and cumulative:
Once something goes wrong, it’s often too late — and very expensive.
If you’re using a Teltonika RUT router, use these tools to check for unusual activity:
tcp.port==80 or httpYou don’t need to change the SIM today — but you do need to stop the exposure.
This will immediately cut off:
And it restores peace of mind.
Many providers now offer private APN SIM cards with fixed internal IPs:
Pros:
Cons:
If you’re already planning a site visit to replace a SIM card, ask yourself:
“Why not also change the router, and solve the problem for good?”
Benefits:
It’s a one-time investment that secures your infrastructure for years to come.
Q: Why is my data usage going up if no one is logging into the system?
A: Because bots are hitting the login page every few seconds. Each hit downloads HTML, CSS, and images, adding up quickly.
Q: Is it enough to just use HTTPS?
A: No. HTTPS encrypts traffic but does not stop unauthorised access or brute-force attempts.
Q: Aren’t private APN SIMs more expensive?
A: They can be slightly more expensive than public IP SIMs, but they offer drastically better security. In the long run, they save money.
Q: What is Iotinix and how does it help?
A: Iotinix is a remote access platform that allows secure connection to your devices over dynamic IP SIMs without public exposure. No fixed IP required.
Q: Can I keep my current SIM cards and just enable VPN?
A: Yes. This is the recommended short-term fix. Port forwarding should be disabled immediately.
Q: Are Teltonika routers secure?
A: Yes. Models like the RUT241, RUT951, and RUTM30 offer VPNs, firewall rules, and traffic inspection tools that support secure deployments.
Public IP SIMs had their time. They were easy. They worked. But in 2025, convenience without security is a luxury no business can afford.
This isn’t about fear. It’s about awareness. The risks are real. The costs are rising. And the alternatives are better than ever.
Whether you go for:
Just don’t do nothing.
You have options. Start with a small step today. Your future systems (and your budget) will thank you.
🔐 Ready to ditch public IPs and secure your IoT infrastructure?
Explore Iotinix — secure remote access for SIM-connected devices without exposure.
📶 Need dynamic IP roaming SIM cards that just work?
Visit RoamingSIM and get connected securely, the right way.
The world of IoT and M2M connectivity is rapidly evolving, and nowhere is that more evident than in the UK. Businesses of all sizes – from CCTV installers and facilities managers to transport operators and energy companies – rely on robust, secure, and remotely accessible SIM card solutions. One of the key features required in such deployments is the availability of fixed, public IPv4 addresses. This guide aims to help UK businesses understand the landscape of SIM providers that offer fixed public IPs, the differences between MNOs, MVNOs, and resellers, and how to make informed decisions for current and future deployments.
There are four MNOs in the UK:
Each operates their own physical infrastructure and cellular spectrum. While they do offer IoT SIMs directly, their services are usually limited to their own networks. Direct relationships with MNOs are often suited to large enterprises needing UK-only deployments with high volume contracts. Fixed public IPs are not commonly offered directly without a custom arrangement.
These providers operate their own core networks, APNs, and IP routing systems. They lease access to the radio networks of the MNOs but control IP addressing, SIM authentication, and service layers. Many offer public or private fixed IPs, multi-network roaming, and secure VPN options.
One of the largest IoT connectivity platforms in Europe. Offers multi-network SIMs with access to EE, Vodafone, O2, and Three. Supports public and private static IPs, with their own APNs. Strong enterprise platform with SIMPro for management. Good fit for high-reliability M2M deployments.
UK-based MVNO offering intelligent mobile data and multi-network roaming. Offers true static public and private IPs, network-level filtering, and extensive UK coverage. Uses custom APNs and routes via Daisy’s infrastructure.
Delivers M2M SIMs with static IP addressing across all UK networks. Private or public IP options available. Unified APN simplifies deployment. Strong support for bonded 4G/5G and failover use cases.
Channel-focused provider with advanced features like Cloudflare-protected public IPs, mobile manager platform, and reseller support. Offers fixed public/private IPs on Vodafone, O2, EE, and Three. Known for flexible commercial terms.
Global provider with UK operations. Offers fixed IP IoT SIMs using APN m2m. Supports all UK MNOs and roaming partners. Well-suited for mobile routers, security, and international deployments.
UK-focused MVNO with strong emphasis on default static IPs. Offers single and multi-network SIMs. Ideal for business continuity and plug-and-play router deployments with fixed remote access.
MVNO using multiple UK networks. Static public or private IPs available. Supports pooled plans and large-scale rollouts. Used in applications like EV charging, ATMs, and retail.
Multi-network and global SIM provider offering both fixed public and private IPs. Known for transparency and bundled router+SIM packages. Uses APN m2mconnect.net. Ideal for CCTV, industrial and remote access.
IoT MVNO with focus on security and resilience. Offers fixed IP, IPsec VPN, and private APNs. Good for smart infrastructure, healthcare, and critical M2M applications.
International SIM provider with strong UK and global reach. Offers fixed IP services using APN iotfixed. Excellent for EV charging, GPS tracking, and global roaming with static addressing.
UK-based provider offering static IPv4 on unsteered roaming SIMs. Uses APN fast.vpn. Specialises in SIMs for CCTV, routers, and failover connections. Offers both public IP and secure VPN.
Legacy provider (now under Aeris/Wireless Logic) known for flexible IP configuration. Fixed public or private IP options, global roaming, and mature management platform for legacy IoT clients.
Evolved from Daisy’s IoT division. Offers multi-network connectivity and static IPs. Supports private APN and VPN options. Ideal for retail, vehicle telematics, and field device fleets.
Developer-friendly global SIM platform (part of Wireless Logic). Offers optional fixed public IPs and private IP with VPN. Competitive pricing and self-serve dashboard.
Estonia-based provider with UK/EU focus. Offers static private IPs (public IP on request) via custom VPNs. Used in cross-border M2M deployments and remote management solutions.
Resellers do not operate a core network. They buy wholesale airtime and IP services from MVNOs or MNOs and repackage it with hardware or value-added services. Many focus on bundling SIMs with routers, remote access platforms, or industry-specific solutions.
These resellers often rely on upstream MVNOs like Wireless Logic, Comms365, or Pangea to deliver the actual SIM and IP services. Their value lies in packaging, integration, industry knowledge, and flexible support.
The UK marketplace for IoT SIM cards with fixed public IPs is mature and diverse. Businesses seeking secure, reliable, and remotely accessible connectivity have multiple options:
When selecting a provider, consider:
By understanding which players control the core infrastructure, offer real IP routing, and specialise in your sector, you can avoid downtime, simplify remote access, and future-proof your M2M or IoT deployment.