Spending Review 2025: Modernise with purpose

Spending Review 2025: A Wake-Up Call for Legacy Modernisation

The UK Government’s 2025 Spending Review has landed and with it, a clear message: digital transformation in the public sector is no longer optional. With increased investment earmarked for AI, data infrastructure, and public service reform, it's evident that the future of government services is digital, intelligent, and agile.

But there’s a catch. You can’t build the digital future on the legacy foundations of the past.

Across the public sector, legacy systems remain a major barrier to progress. Often decades old, these outdated platforms are costly to maintain, vulnerable to and fundamentally incompatible with the digital ambitions outlined in the Spending Review. From deploying AI to improve citizen services or enabling real-time data sharing across departments, legacy infrastructure simply cannot keep up.

That's why legacy modernisation is now mission-critical.

At PDMS, we’ve long advocated that modernisation isn’t just about replacing old systems with new ones. It’s about rethinking how technology supports better public outcomes: more efficient operations, more responsive services, and a better experience for both citizens and staff. It’s about aligning digital infrastructure with strategic goals, not just IT procurement cycles.

The Spending Review offers a unique opportunity for public sector leaders to act. With funding streams opening and political momentum behind transformation, now is the time to prioritise modernisation efforts that have too often been deferred. But delivering successful and meaningful change requires more than just budget. It demands vision, leadership, and a willingness to challenge the status quo.

We believe legacy modernisation should be approached with purpose. That means:

• Understanding the business case: Modernisation isn’t just a technical upgrade, it’s a strategic enabler. From reducing operational risk to unlocking new capabilities, the benefits are tangible and measurable.
• Taking a phased approach: Big bang replacements are risky and expensive. Incremental modernisation - starting with the most critical pain points - can deliver value faster and build momentum.
• Designing for the future: Modern systems must be flexible, interoperable, and cloud-ready. They should support innovation, not constrain it.
• Putting users first: Whether it’s frontline staff or citizens, modernisation should improve the experience for everyone who interacts with government services.

As the Spending Review makes clear, the UK is entering a new era of digital ambition. But ambition alone won’t deliver results. It’s time to tackle the legacy challenge head-on and build the digital foundations our public services deserve. 

To help organisations take the first step, we have developed a Digital Foundations Framework - a pragmatic, step-by-step approach to legacy modernisation focusing on realising benefits early and actionable progress. Our roadmap helps organisations to break down legacy complexity rather than avoiding it and drive transformation without disruption.

At PDMS, we’re ready to help. Let’s modernise with purpose!

To find out how we support, visit our Legacy Modernisation page