​​​​​Realising value through IT post-merger integration in financial services

Across the first half of 2025, financial services therefore accounted for nearly $70bn in announced M&A transaction value, consistently outpacing real estate, industrials, and technology. This concentration of value in large, regulated institutions indicates that integration complexity per deal is increasing, with core platforms, data environments, regulatory reporting, and customer-facing systems increasingly in scope. 

Post-merger integration presents a rare opportunity for financial services institutions to reshape their technology landscape, strengthen operational resilience, and accelerate strategic priorities such as scalability, regulatory compliance, and digital capabilities.² 

As financial services M&A increases in scale and complexity, traditional integration approaches (structure-first integration, milestone-driven, siloed IT integration, and optional change management) are increasingly stretched by legacy technology, regulatory expectations, and constrained delivery capacity. 

In practice, IT post-merger integration (IT PMI) plays a decisive role in determining whether these opportunities are realised. Core ambitions – cost synergies, platform harmonisation, improved data capabilities, and enhanced customer experience – are ultimately delivered through technology decisions and disciplined execution.³ While technical integration is demanding, the real challenge is often organisational: making decisions fast enough, with the right accountability and governance, while maintaining regulatory control. This is where many programmes drift, not so much due to a lack of effort, but due to a lack of integration architecture across people, processes, and technology. 

This article focuses on IT post-merger integration (IT PMI) within larger M&A programmes in the financial services industry. It draws on our experience from large, multi-year integration programmes in the industry across Europe, the Americas, and Asia. 

Based on this experience, the article presents six practical principles that help financial services organisations structure and execute IT PMI programmes in a way that translates strategic intent into measurable outcomes.

1. Establish a shared direction using OKRs 

Successful IT PMI programmes do not fail because organisations work slowly, but because teams work in different directions. If you cannot turn intentions or plans into concrete, measurable results after an integration (for example, after a merger, acquisition, or major organisational integration), then you need one thing very early on: a clear, shared direction that everyone in the organisation agrees on, and that forces people to set priorities and trade-offs, instead of trying to do everything all at once. 

Objectives and Key Results (OKRs) define what an organisation aims to achieve (objectives) and how success is measured (key results).⁴ Unlike traditional KPIs, OKRs make priorities and trade-offs explicit and help align teams working across legacy organisations, functions, and geographies. 

Integration OKRs should be a direct reflection of the deal’s strategic intent and chosen integration approach: stand-alone, fully integrated, or hybrid. This ensures that execution priorities remain anchored in value creation rather than activity completion.

For example, in a full integration, OKRs may focus on migration speed, decommissioning, and risk alignment, whereas in a hybrid integration model, they may focus on dependency reduction, interface stability, and Transition Service Agreement (TSA) exit readiness. 

Ideally, OKRs are defined before day one as part of integration planning. However, they should also evolve after day one, as visibility in the target organisation becomes clearer. 

In financial services IT PMI, this becomes particularly powerful when integration objectives cut across technology, risk, and finance. For example, an objective such as exiting TSAs for core finance and risk systems within a defined, regulatory-approved timeframe forces early alignment on migration sequencing, parallel-run controls, data reconciliation, and audit readiness. 

Moreover, high-performing integration programmes reinforce OKRs with a shared Definition of Done (DoD), ensuring that outcomes are only considered complete once architectural, security, data, and compliance criteria have been met. Together, these mechanisms reduce local optimisation and allow large integration programmes to move decisively in a shared direction. 

2. Create end-to-end accountability

Direction alone does not create progress. Accountability enables execution. In our experience, organisations attempt to deliver IT PMI through vertical structures, where platform owners, domain leads, and functions retain responsibility, while the integration programme expects horizontal outcomes such as consolidated core systems or shared data platforms. This structural mismatch slows decision-making, increases escalation, and ultimately delays value realisation. 

Effective IT PMI programmes introduce end-to-end accountability by making ownership explicit across the full scope of a product, platform, or capability – from infrastructure and applications to operational readiness. In our experience, this typically involves: 

• End-to-end integration leads accountable across business, IT, and operations with authority to make trade-offs across architecture, delivery sequencing and run/operate requirements. 
• Clearly defined decision rights that reduce handovers and avoid escalation by default. 

Clear accountability shortens decision paths and improves execution without adding governance overheads.⁵ 

In regulated financial services environments, end-to-end accountability must extend even further. The receiving organisation is not only integrating technology but also assuming regulatory responsibility. This means accountability must be clear across the first and second Lines of Defence (LoD), including ownership of ICT risk management, control design, evidence production, and risk-informed approvals. What typically goes wrong when integration programmes stall is that decisions are not made with sufficient control, resulting in late-stage rework, delayed sign-offs, and increased supervisory exposure. 

This becomes particularly visible when services are temporarily delivered under TSAs. Even where core services remain with the seller, accountability for integration outcomes cannot be outsourced, especially in financial services where TSAs frequently cover core finance, risk, data, and regulatory reporting platforms that remain subject to supervisory oversight throughout the transition. While TSAs can provide short-term stability, they often create the perception that critical capabilities are still ‘managed’ by the seller, delaying the receiving organisation’s readiness to operate independently. 

Based on our experience, successful TSA exit requires early buyer-side ownership of migration sequencing, parallel-run and control framework, as well as data reconciliation and regulatory engagement. Without a single accountable owner, dependencies persist, regulatory readiness is delayed, and TSA timelines are extended, resulting in increased costs, operational risk, and supervisory exposure.⁶ 

Many integration programmes look well-structured on paper, with hundreds of milestones and detailed plans. Yet delays still occur, and this typically happens when accountability is fragmented across organisations and governance is not designed to support risk-informed decision-making. When this happens, progress becomes activity-driven rather than outcome-driven, and programme control is mistaken for execution. 

3. Govern for outcomes, not output 

As integration programmes scale, governance becomes a decisive lever for maintaining momentum rather than a passive control mechanism. In regulated financial services environments, governance structures often expand rapidly during post-merger integration. While appropriate control is essential, governance that focuses primarily on activities, approvals, and status reporting can dilute ownership and slow decision-making. 

Effective IT post-merger integration governance therefore shifts the focus from monitoring tasks to steering towards outcomes. Governing for outcomes, such as ensuring that all customer data for a given product is served from a single, auditable source approved by Risk and Compliance, creates a shared point of alignment across architecture, controls, data reconciliation, and operational readiness.⁷ 

In practice, outcome-oriented governance is reinforced through iterative planning and frequent, focused review cycles. These short feedback loops reflect how methodologies like Half Double emphasise flow and learning, allowing leadership to surface dependencies early, respond to regulatory findings as they emerge, and intervene decisively when integration risks begin to erode momentum – without adding unnecessary governance overhead.⁸ 

4. Balance integration work and business-as-usual to protect value 

One of the defining challenges in IT PMI is balancing integration delivery with ongoing operations. Financial services institutions must preserve stability, security, and regulatory compliance while executing complex integration work. When this balance is not managed explicitly, teams become overloaded, and delivery quality deteriorates, often during the most critical phases of the programme. 

Capacity allocation is a management decision, not a planning issue. We have observed that organisations managing this tension effectively tend to make a small number of deliberate choices:

This tension typically surfaces when major platform migrations coincide with regulatory remediation, audits, or peak operational periods. Treating integration delivery as disciplined execution rather than incremental work layered onto BAU, allows organisations to sustain momentum while controlling operational risk.⁹ 

5. Make change management a first-class capability 

Technology integration succeeds through people, not systems alone. In financial services IT PMI, the impact of integration is rarely distributed evenly across the organisation. Change pressure concentrates on specific groups, most notably employees transferring from the target entity, who often operate for extended periods across multiple systems, identities, devices, and control environments. These individuals are required to maintain regulatory compliance, customer service, and operational continuity while adapting to new processes, governance, and cultural expectations. 

Managing change during IT post-merger integration requires more than distributing information or delivering training sessions. It demands focused support for the roles most exposed to integration complexity, visible leadership involvement, and practical enablement that helps people carry out their daily responsibilities reliably while systems, processes, and controls change. 

Leading organisations therefore treat change as a core integration capability rather than a supporting activity. This is particularly evident in roles responsible for day-to-day execution under regulatory and operational pressure, such as finance operations or customer-facing service teams, where the ability to perform consistently throughout the transition is critical to maintaining customer trust and control effectiveness. 

For example, staff handling payments, reconciliations, or customer queries may be required to adopt new core systems, approval hierarchies, and reporting routines while maintaining service levels and regulatory accuracy from day one. Successful programmes recognise this pressure and invest in role-specific enablement, supervised cutovers, and visible leadership support that help people operate confidently in the new environment – protecting customer experience and control effectiveness while accelerating adoption.¹⁰ 

6. Apply product thinking to legacy platforms 

The final value lever in IT PMI lies in how organisations treat legacy platforms. Lower-performing integrations treat existing systems as immovable constraints. Higher-performing programmes treat platforms as products with a lifecycle, requiring explicit decisions on what to integrate, what may coexist temporarily, and what must ultimately be decommissioned.¹¹ 

In European financial services, regulatory requirements increasingly demand organisations make explicit lifecycle decisions about legacy platforms during IT post-merger integration. The Digital Operational Resilience Act (DORA) requires financial institutions to maintain end-to-end visibility, resilience, and control over critical information and communication technology assets, including those inherited through acquisitions. Crucially, DORA extends this accountability beyond internally owned platforms to include ICT services delivered by third parties, increasing the importance of supplier oversight, contractual safeguards, and exit readiness as part of the integration approach. 

At the same time, supervisory expectations from the European Banking Authority (EBA) and the European Central Bank (ECB) place strict requirements on information and communication technology (ICT) risk ownership, outsourcing arrangements, and operational accountability. In practice, this changes the tolerance for prolonged coexistence models. Parallel operation of legacy platforms, duplicate control environments, or ‘temporary’ outsourcing setups must be justified not only economically, but also through demonstrable governance, control effectiveness, and evidence production. As a result, extended parallel runs become increasingly difficult to sustain, especially for platforms supporting critical functions. 

We can therefore conclude that treating platforms as products with a defined lifecycle (covering integration, stabilisation, and decommissioning) helps organisations align regulatory compliance, operational resilience, and cost reduction, rather than allowing technical debt and compliance risk to accumulate over time. By explicitly linking platform lifecycle decisions to regulatory and contractual constraints early, organisations reduce late rework, accelerate decommissioning, and avoid value leakage during post-merger integration. 

From integration execution to strategic advantage 

IT post-merger integration is often approached as a finite phase to be completed and closed. In financial services, organisations that extract the greatest value take a different view. They treat IT PMI not only as an execution challenge but as a defining moment for how the organisation makes decisions, manages risk, and delivers change under pressure. 

By setting clear priorities, assigning real end-to-end ownership, governing towards outcomes, and actively supporting adoption, leaders create the conditions to navigate complexity deliberately rather than reactively. Over time, these choices shape how effectively the organisation integrates future acquisitions, responds to regulatory change, and modernises its technology landscape. 

When IT PMI is treated as a repeatable organisational capability rather than a one-off effort, integration programmes deliver more than synergies. They leave the organisation structurally stronger: better able to execute strategy, absorb change, and sustain performance in an environment where complexity is the norm rather than the exception. 

If your organisation is approaching a merger or carve-out, the best time to address these topics is early, when governance, accountability, and vendor strategy are still flexible. Alignment discussions at that stage can prevent months of remediation, parallel-run costs, and operational risk later in the integration. The six principles presented here are intended as a practical starting point. In our experience, the key is not whether organisations know what ‘good’ looks like, but whether they can translate it into execution under real constraints such as regulatory requirements, dependencies, and legacy complexity. 

Sources 

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