Less than three months after he took office for his first term at City Hall, Mayor de Blasio began raising funds for his re-election, records show.

The mayor has been covertly fund-raising around town, according to one source, and depositing donations into the cryptically named “Administrative Account 2014” set up with the state’s Board of Elections on March 25.

The account lists lawyer Joni Kletter, a member of de Blasio’s inauguration committee, as its treasurer.

On Thursday, the mayor also registered his 2017 campaign with the city’s Campaign Finance Board.

“The Administrative Account was set up to pay for expenses that were previously covered by the 2013 campaign, such as non-governmental meals and events,” Dan Levitan, de Blasio’s campaign spokesperson, told The Post.