Phones and emails were out of action at Preston City Council.
It came after the Town Hall had an overnight power cut on Sunday.
Writing on the authority’s Facebook page on Monday morning a spokesman said: “Please bear with us - there has been a power outage overnight and all of our systems are down. This includes all phones and email.
“We are working to get back online as soon as possible.
“Thank you for your patience.”
The system was back up and running by the end of the day on Monday, January 28.