N4 Finsbury Park: why this London postcode has the number 4

After Finchley, before Highbury

Finsbury Park is N4 because of the alphabet. N1 is the Northern district office, and in the Post Office's list of March 1917 the offices after it follow by name: Finsbury Park comes after Finchley (N3) and before Highbury (N5).

See N4 on the map