The problems, which started this morning, were affecting the Barclays website and telephone banking, although the bank said its mobile phone app was working as normal.
A spokeswoman for Barclays said they were working to fix the problems.
She said: “We’re currently experiencing some technical problems - customers are still able to use Barclays mobile banking app to check their balance, make and receive payments.”
People vented their frustration on Twitter, with one user saying “It is driving me mad at the moment.”
Another said: “Their phone lines are down and online banking not working... thanks guys!”
The latest banking problems follow TSB’s huge IT meltdown earlier this year, following a botched IT switch which saw customers locked out of their accounts.