Outer door

The outer door was the first of the two doors of the TARDIS, as used by the First Doctor. Through the outer door was the exterior entrance chamber, followed by an inner door which led to a fourth dimension beginning with the control room. (COMIC: The Secrets of the Tardis)

Following the Last Great Time War, the Doctor dispensed with the inner doors, the outer doors of the police box disguise leading directly into the TARDIS control room. (TV: Rose)

The real-time envelope of the TARDIS would not seal unless the outer doors were fully closed. (TV: The Husbands of River Song)