TSB Bank was fined 48.65 million pounds (U.S. $59.2 million) by U.K. regulators Tuesday after a disastrous IT migration left customers unable to access cash or use online accounts for weeks.

All of TSB’s branches and a large proportion of its 5.2 million customers were affected by technical failures caused when the bank tried to switch to a new IT system in April 2018, according to the Financial Conduct Authority (FCA).

Neil Hodge is a freelance business journalist and photographer based in Nottingham, United Kingdom. He writes on insurance and risk management, corporate governance, internal audit, compliance, and legal...