The album became known as Personnummerpladen (English: The Personal Identification Number Record), as its official title was Larsen's personal identification number.

It was Larsen's third solo album, and the first following the break-up of Gasolin'.

[1] 231045-0637 was recorded in Sweet Silence studios in Copenhagen and produced by Nils Henriksen.

[2] Its style differs from the hard rock of Gasolin'.

By comparison, it is more pop-based and represents the start of the electronic sounds that would dominate his next records, Jungle Dreams [da] and Midt om natten.