Critical IoT connectivity experts.

Connecting the critical moments that matter— with 30 years’ experience, we deliver reliable IoT solutions for Life Critical, Mission Critical and Business Critical needs, keeping over three million devices connected 24/7.

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Life Critical

Protecting people’s safety in high-stakes situations where real-time data is crucial.

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Mission Critical

Supporting the essential infrastructure that keeps a country running.

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Business Critical

Ensuring business continuity where connectivity loss poses serious commercial risk.

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Our Critical Connectivity
capabilities

  • We deliver a complete range of secure, resilient connectivity solutions tailored for life-safety, security, and mission-critical environments.
  • Our portfolio includes multi-network SIMs, patented rSIM, routers, broadband, 5G, and satellite — all fully managed and monitored.
  • Every solution is engineered for high availability, with features such as dual-path signalling, unsteered roaming, and dual-core resilience.
  • Our cloud-based platforms offer full visibility and control across all deployed devices, supported by real-time monitoring and in-life service management.
  • We integrate seamlessly with over 270 Alarm Receiving Centres (ARCs) and support private APNs, VPN compatibility, and regulatory compliance.
  • With over 30 years of experience, we bring proven expertise in large-scale national projects and complex infrastructure deployments.
  • Our UK-based technical teams and Network Operations Centres (NOCs) provide 24/7/365 support to keep your systems running at their best.
About us

We deliver trusted solutions across diverse sectors, many in highly regulated environments:

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Infrastructure

Providing reliable connectivity solutions to keep essential systems operational and resilient, with 24/7 support and proactive monitoring.

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Industrial

Enabling real-time connectivity for efficient, safe project management and compliance.

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Healthcare & Telecare

Providing secure, always-on connectivity to support patient monitoring, emergency response and remote care.

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Building & Security

Ensuring reliable, low-latency connectivity for surveillance, secure communications and threat detection.

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Transport & Logistics

Facilitating continuous fleet communication and tracking, boosting operational efficiency and ensuring compliance.

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Commercial

Improving operational efficiency with scalable, reliable solutions, including point-of-sale connectivity and disaster recovery.

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Retail & Hospitality

Supporting seamless operations and customer experiences through secure, resilient smart solutions.

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Utilities

Providing compliant, protected IoT connectivity to support critical services and uphold public safety standards.

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30

Years of critical connectivity

3
M

Devices with IoT connectivity

24/7

Response and assistance, and rapid resolution

4G/5G

Solutions for 2G, 3G and PSTN Switch-Offs

Talk to us

See how our solutions deliver results—explore our latest case studies:

Statieheld
Retail & Hospitality

Statieheld

How Statieheld unlocked nationwide expansion, streamlined operations, and eliminated connectivity barriers with a powerful multi-network IoT solution.

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Industrial

Philadelphia Scientific

Discover how Philadelphia Scientific UK enhances battery monitoring solutions with our multi-network roaming IoT SIM, ensuring stable global connectivity and seamless data transmission.

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Transport & Logistics

Rewire Security

Discover how Rewire Security leverages our multi-network roaming IoT SIM to ensure reliable GPS tracking connectivity, offering seamless data transmission, flexibility, and enhanced operational efficiency.

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Healthcare & Telecare

Careium

Careium, is a global leader in Technology-Enabled Care (TEC) solutions, offering secure and reliable telecare systems for older and vulnerable people.

Trusted by global brands and top MNOs, we provide solutions that drive success for industry leaders.

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Kings Secure Technologies
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Explore our latest news, information and updates

News

CSL Company Update 2025: Celebrating success together

Recognising and rewarding our staff at the annual CSL Company Update Awards.

Next Starts Now

The Future of Construction: Revolutionising Sustainability with Critical IoT Connectivity

Discover how IoT is transforming the construction industry by enabling smarter, safer, and more sustainable building practices. From real-time monitoring to predictive analytics, IoT is the backbone of modern construction innovation.

IoT in Construction

How AI, ML, RL, and DL Are Transforming Building Management Systems (BMS)

Building Management Systems (BMS) are undergoing a revolutionary transformation with the integration of advanced technologies such as Artificial Intelligence (AI), Machine Learning (ML), Reinforcement Learning (RL), and Deep Learning (DL). ​

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CSL Group Announces Partnership with KPN

CSL Group announces that it has officially become a partner of KPN.

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CSL Named One of the UK’s Best Workplaces for Development™ 2025 by Great Place To Work® UK

We’re proud to share that CSL has been recognised as one of the UK’s Best Workplaces for Development™ 2025, by Great Place To Work UK, ranking 12th in the large-sized company category!

Best Workplaces

Smart Buildings: The Role of IoT and Edge Connectivity in Achieving NetZero Goals

The construction industry is at the forefront of global efforts to achieve NetZero emissions by 2050. ​As one of the largest contributors to energy consumption and greenhouse gas (GHG) emissions, the sector faces significant challenges but also immense opportunities to innovate and transform. Smart buildings, powered by Internet of Things (IoT) and edge connectivity, are emerging as a critical solution to reduce energy use, enhance efficiency, and support sustainability goals. ​This article explores the key findings and data points from recent research to highlight the transformative potential of smart building technologies. ​

Construction IoT