The constabulary has tweeted that it is not receiving calls on that number.
It said work is ongoing to resolve the issue.
The 999 service remains unaffected.
Police 101 fault
Lancashire Police reported a fault with its 101 number this afternoon.
By The Newsroom
Sunday, 24th April 2016, 3:24 pm
Updated Sunday, 24th April 2016, 4:28 pm