In New York City, journalist and compulsive liar Rebecca Bloomwood (Isla Fisher) is an addicted consumer that can not resist shopping fashionable clothes and outfits in fancy shops and has several unplayable debts with credit cards. She dreams on working on the fashion magazine "Alette", owned by the sophisticated Alette Naylor (Dame Kristin Scott Thomas), but she does not succeed in her intent. When Becky loses her job, she drinks a lot of booze with her best friend Suze (Krysten Ritter) and sends an offensive letter to editor Luke Brandon (Hugh Dancy) from the financial magazine "Successful Saving" and an article to Alette to show her potential. However, she unintentionally switches the correspondences in the mailbox and Luke hires her to write a column called "The Girl in the Green Scarf" in his magazine using a simple language and metaphors that could be easily understood by common people. Meanwhile, debt collector Derek Smeath (Robert Stanton) is chasing Becky and she is avoiding him everywhere, saying that he is an ex-boyfriend that is stalking her. When her column becomes a success, Becky is invited to participate on a talk show and Luke and she fall in love with each other. However, her lies and debts put her in a difficult situation with her audience, Suze, and Luke.