Britain's biggest building society was forced to apologise to its customers again after they were locked out of their accounts online for the second time this week.
A message on Nationwide's website yesterday read: "We're sorry to have to tell you that our online bank is unavailable. We are making every effort to restore service as quickly as possible. We apologise for any inconvenience this will cause you."
The building society's mobile banking service was also unavailable last night, but ATMs were operating as normal.
Customers vented their anger on the Twitter website. One wrote: "online banking still not working. Been 3 days now".
Another user commented: "banking down again? What a joke!"
On Tuesday Nationwide apologised after an IT hitch stopped customers from accessing their accounts online.
Last July, the building society was hit by another banking error when nearly three-quarters of a million customers saw debit card payments taken from their accounts twice.
Nationwide corrected those mistakes and promised to reimburse anyone who incurred extra charges as a direct result.