Customers said they were unable to access their accounts either online or in their app.
Although TSB is no longer owned by Lloyds Banking Group, its systems were also affected.
Can't log-in to Lloyds online banking.— Jay Brown🎨 (@EyesWatchin) January 11, 2017
Lloyds' Twitter account said it was "aware of some intermittent issues" and was working to resolve them as soon as possible.
However, at 1.30pm Lloyds said systems were back up and running.
“We are aware that some customers may have experienced issues logging on to internet banking this morning across all Lloyds Banking Group brands.
"This service is now working normally and we apologise for any inconvenience caused," said a spokesperson.