An electrical connector includes an insulative housing and a number of first and second contacts retained therein. The insulative housing defines a first receiving cavity with a first tongue extending thereinto and a second receiving cavity with a second tongue extending thereinto. The second receiving cavity communicates with the first receiving cavity in an up to down direction. The first contacts are disposed on opposite first and second surfaces of the first tongue. Each first contact has a first contact portion protruding into the first receiving cavity and a first tail portion. The second contacts are disposed on a mounting surface of the second tongue. Each second contact has a flat second contact portion exposed to the second receiving cavity and a second tail portion. All first tail portions and second tail portions extend out of the insulative housing and are arranged in a row.