"Don't Lose My Number" is a song by Phil Collins from his third solo album No Jacket Required. The single was not released in the UK, though it peaked at No. 4 in the U.S. in September 1985. The B-side, "We Said Hello Goodbye" was released as a bonus track on the CD for No Jacket Required.
The song is about some young man named Billy whom the singer is hoping to find (and hopes Billy still has the singer's number). The song describes Billy being pursued by some shadowy organisation. Collins has said that he actually wrote most of the song during the recordings for his debut solo album, Face Value. Collins also states that the lyrics were improvised, and that he himself does not fully understand what they mean. Stephen Holden of the New York Times also agreed that the lyrics were very "vague, sketching the outlines of a melodrama but withholding the full story".