The Financial Conduct Authority has said resilience from technology failures will be one of its main focuses in its supervision of the financial services sector.
It comes after several large companies struggled with large scale technology upgrades during 2018 - notably Aegon, Aviva and TSB.
In its Approach to Supervision, published today, the FCA said it took a dim view of companies which failed to mitigate the harms posed by their own technology.
It said: "Technology is fundamental to how we do business in a modern world. Our rules require firms to have appropriate systems and controls to manage and mitigate the risks of harm. These systems and controls help to ensure firms are resilient in the advent of a cyber-attack or a technology failure.
"Disruption from cyber-attacks or technology failures can cause significant harm to consumers or markets through lost personal or confidential data, financial loss from fraud, disruption to services or ability of the financial system to function on a day to day basis. Equally, innovation can bring benefits from increased efficiency and new services."
The FCA said companies should also have effective processes to identify, manage, monitor and report the risks to which they could be exposed when it comes to cyber attacks.
Last year both Aegon and Aviva struggled to get service levels back to normal after replatforming.
Aegon, which bought Cofunds for £140m in 2016, merged it with its in-house platform over the May Bank Holiday weekend last year but the platform was beset by a range of problems, including long waiting times on the phone and advisers struggling to get income.
Meanwhile Aviva's platform was unavailable for six days after it moved to tech company FNZ in January, and there were ongoing issues with the new client reporting function and problems which affected payments for people in drawdown, while advisers said they were not getting their payments through the platform.
Meanwhile TSB faced an FCA investigation last year after nearly 2m people were locked out of online banking services when it began moving its customer data from a system controlled by its former owner, Lloyds Banking Group, to a system built by its new owner, the Spanish banking group Banco Sabadell.
The FCA said its other priorities would be to make sure companies are not used as conduits for financial crime such as money laundering, as well as consumers being sold products that are unsuitable for their needs and being misled by firms or not being given enough information to understand a product’s total cost or the risks and obligations they may be taking on.
The regulator said it also had concerns about business models which create risk of harm to consumers or markets.
It said: "A business model under significant pressure for performance or on the verge of failure can create risks to consumers. The business may be tempted to go to extraordinary lengths to improve performance, such as engaging in higher risk lending or aggressive sales practice.