Customers of UK direct bank Intelligent Finance (IF) were unable to access accounts on Sunday and Monday after hardware installed to increase capacity caused an outage.
IF - a division of Halifax - closed on Sunday to carry out a routine IT upgrade and to increase capacity. The bank was put back online that afternoon.
However, IF says that on Monday morning it noticed the hardware installed to increase potential capacity was slowing systems, causing customer outage.
"Given we are a telenet bank and are therefore available by phone, we took the decision to take the Web down to allow us to reinstall the hardware onto our servers," says IF in a statement.
Press reports claim that telephone customers have been suffering delays as a result of the increased strain on the system caused by the Internet outage.
IF says that its systems have been operating normally since 5:20am this morning.