Continuity mistake: When Edward picks Vivian up at the hotel for their first dinner out, he walks up to the phone bank and picks up the phone with his left hand and his briefcase is in his right hand (down at his side). When he speaks with the manager, he hangs up the phone still with his left hand and then reaches up on the counter with his right hand to get his briefcase (which he never set up there). He keeps his right arm down at his side the whole time.
Continuity mistake: Vivian has just taken over driving the car and its aerial is down (located on the front left of the car), in the next scene the aerial is up. After the "talking in the car" scene the aerial is still up, however in the scene after that when she turns the corner the aerial is down. (00:13:20 - 00:14:35)
Continuity mistake: When Vivian and Edward are arguing, she asks for her money, so he reaches for his wallet and takes the money out. When he drops the money on the bed, part of the money is lying on the corner of his suit jacket. After Vivian walks out, when he turns to see if she took the money, it is not lying on his jacket, but at the edge of the bed.
Continuity mistake: In the final scene when Edward and Vivian meet on her fire escape, as the camera angle changes from panning behind Edward to get a shot of Vivian's face and vice versa, Vivian is taller than Edward in one shot and then he is taller than her in the next. This continues throughout the entire scene.