On October 10 Billie Gumble was reported missing.
Police say they are concerned for the 15-year-old’s welfare.
She was last seen wearing a green velour tracksuit with a red stripe up the arms and legs.
She is possibly wearing green Nike trainers and carries a brown and beige large Michael Kors bag.
Billie has links to Enfield and Watford.
Anyone with information is asked to call Loughton police station on 101.
You can also contact the Missing People charity with any details you may have, on Freefone 116 000