OT cybersecurity in manufacturing across the UK has become a board-level priority as ransomware groups increasingly target production environments rather than just office networks. With manufacturing accounting for 17% of all cyber attacks in 2025 — nearly double the previous year — and the NCSC reporting 204 nationally significant cyber incidents in a single year, the threat to your shop floor is real and growing. This practical guide explains what OT cybersecurity means for UK manufacturers, where the biggest risks lie, and what you should be doing about it now.
Last updated: 26 March 2026
What Is OT Cybersecurity and Why Does It Matter for Manufacturing?
Operational technology (OT) refers to the hardware and software that monitors and controls physical processes in your factory — SCADA systems, programmable logic controllers (PLCs), human-machine interfaces (HMIs), industrial sensors, and the networks that connect them. OT cybersecurity is the practice of protecting these systems from cyber threats that could disrupt production, compromise safety, or cause physical damage to equipment.
The critical difference between IT and OT security is what is at stake. A breach of your office email system is disruptive. A breach of your OT network can halt production lines, damage machinery, corrupt batch records, and — in the worst cases — create genuine safety hazards. According to the UK Government’s Cyber Security Breaches Survey 2025, 43% of UK businesses experienced a cyber breach or attack in the past year, with the figure rising to 74% for large businesses. For manufacturers running connected production environments, the exposure is even greater.
The problem is that many OT systems were designed decades before cybersecurity was a concern. They run on legacy operating systems, use unencrypted protocols, and were never intended to be connected to the internet. Yet as manufacturers pursue digitalisation and Industry 4.0, these systems are increasingly networked — creating vulnerabilities that attackers are actively exploiting.
The Biggest OT Cybersecurity Threats Facing UK Manufacturers
Understanding the specific threats helps you prioritise your defences. Here are the risks that matter most for UK production environments in 2026:
- Ransomware targeting OT networks — attackers now specifically seek out production systems because halting a factory creates immediate financial pressure to pay. The 2025 attack on a major UK automotive manufacturer shut production lines for weeks and caused estimated damage of nearly two billion pounds across the supply chain.
- Lateral movement from IT to OT — most OT breaches start with a compromised office computer. The attacker gains a foothold through a phishing email, then moves across the network to reach production systems. Without proper segmentation between IT and OT networks, a single clicked link can reach your PLCs.
- Insecure remote access — many manufacturers allow equipment vendors to remotely access OT systems for maintenance. Poorly configured VPNs and shared credentials create open doors that attackers routinely exploit.
- Legacy systems with known vulnerabilities — SCADA systems and PLCs running on Windows XP or other unsupported operating systems cannot be patched against new threats. They require compensating controls such as network isolation and monitoring.
- Supply chain compromise — attackers target your technology suppliers to gain indirect access to your production environment. A compromised software update or a breached integrator can introduce threats directly into your OT network.
- Insider threats and human error — operators connecting personal devices to production networks, engineers using default passwords on control systems, and staff falling for social engineering attacks all create exploitable gaps.
Practical Steps to Strengthen OT Cybersecurity in Your Factory
The NCSC’s Secure Connectivity Principles for Operational Technology, published in January 2026 in partnership with international agencies, provides an authoritative framework for securing OT environments. Here is how to apply its core principles in a manufacturing context.
Segment your IT and OT networks. This is the single most important step you can take. Your office network (email, ERP, file servers) and your production network (SCADA, PLCs, HMIs) should be separated by a properly configured firewall or demilitarised zone (DMZ). Traffic between the two should be strictly controlled and monitored. If an attacker compromises a laptop in your sales office, they should not be able to reach your production controllers.
Know what you have. You cannot protect what you cannot see. Conduct a full inventory of every device on your OT network — every PLC, every HMI, every sensor, every switch. Document the operating system, firmware version, and network connections for each. Many manufacturers are surprised to discover devices on their production network that nobody knew existed, including legacy equipment connected years ago and never decommissioned.
Control remote access rigorously. Every external connection to your OT environment should use multi-factor authentication, be time-limited, and be logged. The NCSC guidance specifically recommends that all connections to OT environments should be initiated outbound from within the OT network, avoiding exposed inbound ports. Vendor access should be granted only for the specific systems they need, only for the time required, and should be monitored throughout.
Maintain offline backups of critical OT configurations. If ransomware encrypts your SCADA server, you need to restore it without paying a ransom. Keep verified, offline copies of PLC programmes, HMI configurations, and all critical OT system data. Test your ability to restore from these backups regularly.
Building an OT Cybersecurity Programme for Manufacturing
Addressing OT cybersecurity in manufacturing across the UK requires more than one-off technical fixes. It requires an ongoing programme that brings together IT, operations, and senior management. The Make UK Executive Survey 2026 found that 55% of manufacturers plan to increase cybersecurity investment this year, up from 45% the previous year — a clear sign that the sector recognises the urgency.
A practical OT cybersecurity programme for a mid-sized manufacturer should include:
- Joint IT-OT incident response planning — run tabletop exercises that simulate a cyber attack crossing from IT into your production environment. Make sure your IT team, plant managers, and maintenance engineers all know their roles.
- Regular vulnerability assessments — scan your OT network for known vulnerabilities, default credentials, and misconfigured devices. Do this carefully — aggressive scanning can disrupt sensitive OT equipment.
- Staff awareness training — your shop floor operators are part of your security perimeter. Train them to recognise social engineering attempts, report suspicious activity, and follow secure practices when connecting devices to production networks.
- Supplier security requirements — include cybersecurity clauses in contracts with OT vendors and integrators. Require them to meet minimum security standards before granting them access to your production environment.
- Board-level reporting — present OT cybersecurity risk in business terms: potential production downtime, financial impact, customer contract implications, and insurance requirements. The board needs to understand this as a business risk, not just a technical issue.
OT Cybersecurity and the Role of IT Leadership in Manufacturing
One of the most common gaps in OT cybersecurity for manufacturing in the UK is the absence of senior IT leadership that understands both the technology and the production environment. Many manufacturers have an IT manager who looks after the office network and a maintenance team that manages the production equipment, but nobody who bridges the two and owns the overall cybersecurity posture.
This is precisely where a fractional CIO or virtual IT director with manufacturing experience adds significant value. They can assess your current OT security posture, design and implement a segmentation strategy, establish vendor access controls, create an incident response plan, and present the risk clearly to your board — all without the cost of a full-time senior hire.
Frequently Asked Questions
What is the difference between IT security and OT cybersecurity?
IT security protects business information systems such as email, databases, and cloud applications, where the priority is data confidentiality and integrity. OT cybersecurity protects the systems that control physical processes — production lines, SCADA systems, PLCs, and industrial sensors — where the priority is safety, availability, and operational continuity. A cyber attack on IT systems causes data loss; an attack on OT systems can halt production and create physical safety risks.
Do UK manufacturers need Cyber Essentials for OT systems?
Cyber Essentials certification currently focuses on IT systems rather than OT environments. However, many customers and supply chain partners now require Cyber Essentials as a minimum standard, and its principles — boundary firewalls, secure configuration, access control, malware protection, and patch management — apply equally to OT networks. The NCSC’s separate OT-specific guidance provides a more comprehensive framework for production environments.
How much does OT cybersecurity cost for a mid-sized manufacturer?
Costs vary widely depending on the complexity of your production environment. A basic OT network assessment and segmentation project for a single-site manufacturer typically costs between £15,000 and £50,000. Ongoing monitoring, vulnerability management, and incident response planning add annual costs of £20,000 to £60,000. These figures are modest compared to the potential cost of a production-halting ransomware attack, which can run into hundreds of thousands of pounds per day of downtime.
Can we secure legacy SCADA systems that cannot be patched?
Yes, through compensating controls. Isolate legacy systems on their own network segment with strict firewall rules. Monitor all traffic to and from these systems for anomalous behaviour. Remove any unnecessary network connections. Use application whitelisting where the operating system supports it. Maintain verified offline backups of all configurations. Plan for eventual replacement, but in the meantime these controls significantly reduce the risk.
Take the Next Step
Protecting your production environment from cyber threats requires strategic IT leadership that understands both the technology and manufacturing operations. Bailey & Associates provides IT-OT integration and cybersecurity guidance specifically for UK manufacturers, with over 15 years of manufacturing IT experience, vendor-neutral advice, fixed monthly pricing from £2,000/month, and no long-term tie-ins. Whether you need an OT security assessment, a network segmentation strategy, or ongoing cybersecurity leadership, we can help. Book a free discovery call today.
Related Service: Manufacturing IT Services — Learn how Bailey Associates can help your manufacturing business.
