It was founded in 1920 as the Norwegian Municipal Workers' Union, a split from the Norwegian Union of General Workers.[1][2] Its chairman the first fifteen years was Gunnar Sethil.[3] On founding, it had 3,280 members, and this grew steadily. The Norwegian Tramway Union merged in during 1921, followed by the National Association of Municipal Officials in 1923, following which, it renamed itself as the NKF.[4]