Technology transformation is now a strategic imperative for financial services firms. From core banking modernisation and cloud migration to advanced analytics, AI and machine learning, firms are rethinking the technology foundations that underpin how they operate, serve clients and grow.

The ambition may be clear, but delivery is often harder than expected.

Across the sector, transformation timelines are slipping, with third-party dependencies a persistent cause. As firms place more critical elements of their change programmes in the hands of external providers, delays can quickly compound, putting pressure on delivery, increasing costs and creating wider programme risk.

Recent regulatory developments in the UK and EU have brought third-party risk into even sharper focus, underlining just how central suppliers have become to the operational resilience of financial institutions. They also reinforce an important point: transformation programmes are now only as strong as the third-party ecosystem they depend on.

Here are five of the main reasons why supplier dependency is driving delay across financial services transformation programmes.

Growing reliance on a small number of critical third parties

Financial services firms have become heavily dependent on a concentrated group of technology providers, including cloud providers, payment processors, data providers and infrastructure vendors. Regulators have explicitly recognised the risks this concentration creates.

Transformation programmes often rely on these same providers for critical delivery. So, when a supplier experiences capacity constraints, security incidents, operational disruption or internal delivery delays, the impact rarely stays contained. It can ripple across multiple firms at once, affecting priorities, timelines and delivery confidence.

And in practice, firms cannot simply switch supplier part-way through a programme. Integration complexity, regulatory approvals and contractual lock-in make that extremely difficult.

Increasing regulatory scrutiny is slowing delivery

Regulatory regimes are placing growing emphasis on critical third parties as part of a broader effort to manage systemic risk. In the UK, this includes the Operational Resilience and Critical Third Parties oversight regimes, alongside alignment with the EU’s Digital Operational Resilience Act (DORA).

That means firms are now expected to take a much more rigorous approach to managing third-party risk, including:

• Enhanced due diligence
• Detailed contractual provisions
• Ongoing monitoring and reporting
• Resilience testing
• Exit and contingency planning

As a result, transformation programmes must now accommodate more regulatory checkpoints, more documentation and more testing cycles. Suppliers themselves are also working through new compliance obligations, which can affect delivery capacity or force services to be redesigned mid-programme.

Complex multi-vendor environments are increasing interdependency risk

Modern transformation programmes rarely depend on a single provider. More often, they involve a mix of:

• Cloud providers
• Systems integrators
• Software vendors
• Payment service providers
• Data providers
• Cybersecurity managed service partners

That creates a more interconnected delivery environment and with it, more points of failure.

Misaligned delivery schedules, system integration challenges, disputes over accountability for defects, and slower decision-making caused by shared ownership can all introduce friction. What looks manageable at individual supplier level can become much harder to control when dependencies begin to stack up across the programme.

To better manage those interdependencies and strengthen alignment across suppliers, firms should adopt robust third-party and contract management processes, establish clear requirements from the outset, and use joint steering committees with senior vendor representation.

A cross-vendor design authority can help protect architectural coherence, supported by dependency forums that surface and resolve issues collaboratively. An integrated PMO, common delivery methodology, and shared definitions of requirements, milestones, outputs and quality gates can also help drive more consistent and coordinated delivery across all parties.

Governance and oversight challenges inside firms can add further drag

Even where internal governance is strong, many firms still find it difficult to manage supplier performance effectively. Common challenges include:

• Incomplete visibility into supplier subcontractors
• Over-reliance on supplier-provided timelines
• Insufficient internal technical expertise to challenge assumptions
• Slow internal decision-making driven by risk-averse cultures

Regulators are clear that firms remain accountable for their own resilience, even where services are outsourced. That means effective supplier oversight is not optional. But it also means firms must put time and effort into controls, governance and challenge — all of which can slow delivery if not built into the programme in the right way.

Heightened cyber and resilience requirements are adding complexity

Financial services firms must be able to show that new technology meets demanding resilience, cybersecurity and continuity standards, and that security and privacy are embedded into change by design.

Under the UK’s new rules, critical third parties must maintain detailed records, carry out self-assessments, and report risks including supply chain vulnerabilities.

For transformation programmes, that can translate into additional penetration testing, failover testing, resilience assessments and data migration checks. It can also mean delays while suppliers remediate vulnerabilities, alongside longer review and approval periods.

Why vendor dependency is a critical risk for financial services transformation

Technology transformation in financial services is uniquely exposed to supplier-related delay because:

• The sector is structurally dependent on a small number of critical providers
• Regulatory expectations around resilience, oversight and assurance are rising
• Supplier disruption can have system-wide consequences
• Multi-vendor architectures create interdependencies that amplify delay
• Firms cannot easily substitute suppliers when issues emerge

As regulatory oversight of critical third parties continues to strengthen, firms need to adapt how they design and deliver transformation. That means managing multiple vendors in a genuinely integrated way, building stronger supplier risk frameworks, setting more targeted contractual arrangements and requirements, investing in multi-cloud and modular architectures, and embedding regulatory compliance from the outset rather than retrofitting it later.

Our Technology Risk Assurance team have extensive experience supporting clients through technology transformation, including real-time assurance as programmes are being delivered.

To discuss how we can support your transformation journey and help you manage programme and third-party risks more effectively, please contact Riza Unal, Sheila Pancholi or Steven Snaith.

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