Skip to main content
NFRisk Non-Financial Risk advisory Start a Conversation
NFR-0051 Evidence-controlled risk scenario

TSB Bank plc

When the data migrated successfully, was the platform ready?

The FCA and PRA found that TSB's data migrated successfully in April 2018, but the new platform failed immediately; disruption affected all branches and a significant proportion of 5.2 million customers, with £48.65 million in combined penalties.

Technology & Change Risk Operational Resilience Third-Party & Concentration Risk Change & release management System & back-out testing Operational resilience Third-party risk Governance & escalation Control assurance

Documented impact

£48.7m Combined FCA and PRA penalties
£32.7m Customer redress paid
5.2m customers Customer base; a significant proportion was affected

Authoritative findings

The documented event

Over the weekend of 20-22 April 2018, TSB migrated most corporate-system operations, customer services and customer data to a newly built platform. The FCA and PRA found that the data itself migrated successfully, but the platform immediately experienced technical failures. Branch, telephone, online and mobile banking were disrupted; all branches and a significant proportion of TSB's 5.2 million customers were affected, and the bank did not return to business as usual until 10 December 2018. TSB paid £32.7 million in customer redress. In December 2022, the FCA and PRA imposed combined penalties of £48.65 million for operational-risk-management and governance failures, including inadequate organisation and control of the migration programme and inadequate management of outsourcing risks arising from a critical third-party supplier.

Hypothetical institutional scenario

How might the same control pattern appear?

A migration reconciles every customer record successfully. The production platform, however, has not been demonstrated under realistic transaction volume, failure and recovery conditions, and key supplier-readiness evidence is largely self-attested. The successful data migration is treated as a proxy for end-to-end service readiness. Minutes after go-live, customers cannot reliably access the services that present and use the data.

Stress-test questions

Questions for challenge and assurance

  1. Programme

    Are data-migration integrity and live-platform readiness governed as two separate go-live decisions with separate accountable sign-offs?

  2. Technology

    Has the production platform been tested under realistic volume, dependency failure, recovery and customer-journey conditions?

  3. Operations

    Which critical supplier-readiness assertions have been independently verified rather than accepted through self-attestation?

  4. Risk committee

    Can governance stop go-live when reconciliation has passed but platform, resilience or supplier evidence remains incomplete?

NFRisk practitioner interpretation

Control implication

Completeness and correctness of migrated data and operational readiness of the platform serving that data are separate control decisions. A go-live gate should require independent evidence for each: reconciliation and integrity controls for the data; performance, capacity, recoverability, end-to-end service outcomes and supplier readiness for the platform. Passing one gate does not provide evidence that the other has passed.

Framework relevance

Explicitly labelled analytical mappings

Retrospective relevance

Retrospective regulator-linked relevance: UK operational resilience

The FCA later used the TSB migration incident as an example in CP19/32, its consultation on operational resilience and impact tolerances. This establishes retrospective relevance; it does not mean the later framework applied to the 2018 event.

UK operational resilience · Financial Conduct Authority / Prudential Regulation Authority / Bank of England

Evidence register

Primary and supporting sources

  1. Financial Conduct Authority / Prudential Regulation Authority

    TSB fined £48.65m for operational resilience failings (opens in a new tab) 20 December 2022 · Authoritative primary source

  2. Financial Conduct Authority

    Final Notice: TSB Bank plc (opens in a new tab) 20 December 2022 · Authoritative primary source

  3. Financial Conduct Authority

    CP19/32: Building operational resilience (opens in a new tab) 5 December 2019 · Authoritative primary source

Publication note

A documented external event—not an NFRisk client engagement.

The named organisations are included because authoritative sources document the event. Their inclusion does not imply that they are or were NFRisk clients, that they endorse this analysis, or that NFRisk participated in the event or response. Framework relevance and NFRisk practitioner interpretation are analytical layers applied after the event.

Return to the Risk Scenario Library

From scenario to mandate

Test the equivalent control assumption in your environment.

NFRisk can use this scenario as a starting point for a focused structural diagnostic, risk-architecture review or delivery-assurance discussion.

Start a conversation