[4] The district originally consisted of parts of the parishes of Chipping Barnet in Hertfordshire, and Monken Hadley and South Mimms in Middlesex.

The Local Government Act 1888 adjusted the county boundaries in 1889, so that the entire district was in Hertfordshire; forming part of a long, thin protrusion into Middlesex surrounded by that county on two sides, to the north and south.

Its former area was combined with that of other districts to form the present-day London Borough of Barnet.

The urban district was divided into six wards for elections: Arkley East, Arkley West, Barnet North, Barnet South, Totteridge East and Totteridge West.

For elections to Parliament, the urban district was part of the constituency of: In 1945 St Albans was divided as an emergency measure because its electorate exceeded 100,000 voters, with the urban district becoming part of the new constituency of: Great Britain Historical GIS / University of Portsmouth, Barnet UD (historic map).