For the TSB case what was the cause of the outage at the heart of the case?

Step 1: Understanding the TSB Case

The TSB outage in 2018 was caused by a failed IT migration from its old banking system to a new one.

The transition locked millions of customers out of their accounts for weeks, resulting in financial

losses and reputational damage.

Step 2: Why Option C Is Correct

TSB attempted to move customer data to a new banking platform, but serious defects in the

migration process led to service failures.

PRMIA and UK Financial Conduct Authority (FCA) reports confirmed that poor IT risk management

was a key failure.

Step 3: Why the Other Options Are Incorrect

Option A ("Liquidity squeeze by hedge-fund")

Incorrect because TSB's failure was due to IT migration issues, not a liquidity crisis.

Option B ("Sub-standard risk pricing and risk management")

Incorrect because pricing models were not the cause—it was an IT system failure.

Option D ("IT models did not work if prices were discontinuous")

Incorrect as this issue is more common in high-frequency trading failures, not banking system

outages.

PRMIA Risk Reference Used:

UK FCA Investigation on TSB Incident – Confirms IT migration failure as root cause.

PRMIA IT Risk Management Framework – Highlights risks of major IT transitions.

Final Conclusion:

The TSB outage was caused by a failed IT migration, making Option C the correct answer.