The Bank of England has launched an official probe after a key payment system that transfers billions of pounds between banks was suspended.
It is also used by solicitors at the end of the house-buying process, so some movers were stuck for hours because sales could not be completed.
Bank of England governor Mark Carney said he had launched “a thorough, independent review” into the problem. “The review will cover the causes of the incident, the effectiveness of the Bank’s response and the lessons learned for future contingency plans,” the Bank said in a statement.
An institution was added to the Bank’s Real-Time Gross Settlement system, which underpins CHAPS, at the weekend which created a problem when it was supposed to restart on Monday. It normally operates between 0600 and 1600 on weekdays.
The system was down until about 1600 but a statement suggested all payments should now be processed by the end of the day.
“To help customers and to ensure payments can be processed today CHAPS is extending its operating times until 1940 BST. Customers are advised to contact their own bank for any queries they may have on their specific payments,” said a CHAPS statement.
There are about 5,000 homes bought a day in the UK on average, although Friday is the most popular moving day. About 3,000 completions were expected during the day.
The CHAPS system moves billions of pounds every day between Britain’s main banks and building societies. The latest figures show that in 2013 it was used to process an average daily total of 138,000 payments with a combined value of £277 billion.
It is used to move money around the financial system, mainly for very high-value payments. It is used for short-term lending between financial institutions, foreign exchange and derivative-related payments. In 2012-13 the average payment was £2.1 million, but 78% of payments were below £100,000.
The highest ever settlement figure in one day was for £446 billion on 28 September, 2007, during the early part of the financial crisis.
Sometimes it is used by individuals who, for example, want to buy a high value car and need to make a same day, guaranteed payment. There is a charge of about £25 or £30 for an individual who wants to use the system, and the payment generally needs to be made by 1500.
Jonathan Smithers, vice president of the Law Society, said: “It is critical for solicitors to have access to this system for house sales and purchases and many other commercial transactions that rely on a payments scheme that processes and settles important and time-dependent payments in sterling.
“We are talking to the relevant bodies to see if we can obtain some understanding of why the system has failed and assurances that this will not occur again.”
Andrew Tyrie, chairman of the Commons Treasury Committee, said: “A crucial part of the UK’s financial infrastructure failed for several hours. I will be writing to the Bank of England to find out why.
“The whole economy depends on a reliable payment system. We need to have confidence that the cause has been found and addressed.”