The 31-year-old singer said she had "learned her lesson" after she was spotted talking on the phone while driving on Charing Cross Road, central London on April 4, reported Sun online.
She was then taken to nearby Holborn Police Station where she was charged with two driving offences.
"At 6pm Miss Harding was driving north down Charing Cross Road at the same time when PC Stevens was cycling in his uniform.
"He noticed the vehicle swerve so he looked over and noticed that she was using a mobile phone pressed to her right ear. She was eventually stopped by other officers and said she was lost," David Davies, prosecuting, told Highbury Magistrate's Court today.