Changing critical systems in government IT

IT within government has been shifting in prominence for some time. Traditionally seen as a support service quietly enabling policy, administration and service delivery, it now finds itself centre stage.

This evolution has been gradual but decisive. Some government systems have always been deemed critical national infrastructure (CNI): communications for emergency services, defence systems, or national electricity grids, to name a few. These systems are rightfully protected and monitored with a high degree of rigour. But in practice, the landscape has changed. Many services delivered by government IT teams that were once considered routine are now business-critical. A failure today could affect millions of citizens, disrupt essential operations, or erode public trust.

So what’s changed and what does this mean for IT leaders?

The changing definition of critical infrastructure

Traditionally, CNI has referred to systems whose loss would cause significant harm to national security, the economy or public health. This definition still holds, but it increasingly fails to account for the reality of modern government operations. 

Consider services like digital identity platforms, online tax registration, submission and revenue services, benefits and welfare processing systems, and immigration and visa application systems. These are not just web portals or administrative platforms. Their availability underpins the delivery of core public functions. If they go down, the impact is immediate and widely felt financially, operationally and politically. In short, services that were once considered non-critical are now operating in a critical context.

Factors driving changing risk factors

Several forces have combined to change the risk profile of government IT:

• Digitisation of public services: government has embraced digital channels as the default route for accessing services. Many departments no longer offer a paper-based or in-person alternative. This makes the digital system itself the primary point of service and therefore business critical.
• Increased dependency between systems: modern service delivery often depends on integrations across departments. Data flows between systems and decisions are made using inputs from multiple sources. When one part of the chain fails, the consequences ripple across the system.
• Rising cybersecurity threats: government platforms have become targets for cyberattacks, from ransomware to sophisticated nation-state threats. As more services move online, the potential surface area for attack grows, particularly for systems not historically treated as high-risk. With unprecedented speed and scale, AI is enabling attackers to bypass legacy systems and overwhelm security teams. According to our latest research, 55% of public service technology leaders acknowledge that AI is outpacing their security capabilities.
• Real-time demand: whether it’s a benefits application or a border decision, many services now operate in real time. Citizens, businesses and civil servants expect services to be available, fast and reliable. Downtime is no longer tolerated.
• Data-driven government: decision makers increasingly rely on dashboards, analytics and real-time insights to guide policy. When the data pipeline fails, so too does the ability to govern effectively.

What this means for government IT functions

A key point to recognise is that while some government IT services are formally designated as CNI, others are only treated as such in practice. They may not be subject to the same protections, but their failure would be just as disruptive. This presents a grey area. The IT department may recognise a system’s criticality, but the wider organisation stakeholders, policy leads or delivery directors may still view it as a back office tool. This misalignment can lead to underinvestment, missed risks or gaps in operational support. It’s important to close that gap.

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The implications of this shift are wide reaching. IT leaders should reassess their critical systems list and not rely solely on legacy classifications. Revisit which systems are considered mission critical based on impact rather than historical labels. This could include systems supporting revenue collection, citizen identity or large scale case management. 

IT leaders should build resilience into design in preparation for failure. Resilient architecture, load balancing, failover strategies and robust test environments are now baseline requirements, not luxuries. IT leaders should improve observability if a system fails; how quickly can you detect it, diagnose the issue and recover? Good monitoring and observability practices are vital, especially in integrated environments. IT leaders should embed security earlier.

Mission-critical systems should adopt zero-trust principles, secure-by-design approaches and proactive vulnerability management. Security can’t be a bolt-on. IT leaders should treat service operations as strategic. Too often operational support and incident response are treated as reactive functions, but in a mission-critical context, these become strategic. Response speed, root cause analysis and system recovery are all indicators of organisational maturity.

Bringing policy and IT closer together

Another practical step is improving the relationship between policy, service design and technology. Decisions about funding, scope or service models should be made with a full understanding of IT impact or risk. If IT leaders can articulate the criticality of systems in business terms — impact on citizens, revenue or legal obligations — then decisions can be better informed. There’s also an opportunity to use metrics, dashboards and reporting to surface operational risk. For example, highlighting the top five most fragile or unsupported systems on a CIO dashboard can help guide investment.

Avoiding the cost of inaction

When systems aren't treated as mission critical, they often lack the engineering rigour and investment needed to be resilient. This can result in service outages at scale, delayed payments or decisions for citizens, reputational damage to the department, financial penalties or legal challenges and a loss of public trust.

The private sector has already adapted to this reality. Digital customer services are now protected, scaled and supported with the same seriousness as core banking systems. Public sector IT can learn from this transition and follow suit.

Conclusion

The line between CNI and business-as-usual IT is becoming less meaningful in practice. The systems that run welfare, tax, identity and public services are now integral to the nation’s ability to function. For government IT teams, this means stepping into a role of higher visibility and greater responsibility. It also means advocating for design practices, funding and support models that reflect the reality: more of your portfolio is mission critical than ever before. By recognising this shift and adapting accordingly we can help ensure government services remain resilient, secure and trusted in an increasingly digital world.