Many Lloyds TSB and Halifax customers have reported being unable to log into their online accounts this morning, though the banks say the problem is now fixed.
Lloyds Banking Group, which runs both banks, says: "For a short period some customers received a slower service but it is back to normal. We apologise for any inconvenience."
When members of the MoneySavingExpert.com team tried to get into their Lloyds TSB accounts at 9.45am the following message appeared: "We're sorry but internet banking is currently unavailable. Please try again later."
Similarly, a message on the Halifax website at the same time said: "Unfortunately there has been a technical problem. This transaction has not been completed."
An hour later, MSE staff could get into their Halifax and Lloyds accounts again.
Many customers took to Twitter to complain of being unable to access their account.
Banks sometimes suffer temporary internet banking outages.
RBS, NatWest and Ulster Bank customers have experienced much worse, however. Millions had been unable to use their account properly for weeks after an IT crash, with the Ulster problems still ongoing.
O2 mobile customers are also having major problems accessing their network on a bad day for technology.