In the period 1896-99 sixty urban districts were formed and twenty-two abolished, a net increase of 38, bringing the total number of urban districts to 813.
In the 1900s forty-six urban districts were formed and forty-one abolished, a net increase of 5, bringing the total number of urban districts to an all-time high of 818.
In the 1910s twenty-one urban districts were formed and forty-one abolished, a net decrease of 20, bringing the total number of urban districts to 798.
In the 1920s twenty-five urban districts were formed and thirty-nine abolished, a net decrease of 14, bringing the total number of urban districts to 784.
In the 1930s forty-one urban districts were formed and two hundred fifty-three abolished, a net decrease of 212, bringing the total number of urban districts to 572. This was largely due to the County review orders instigated by the Local Government Act 1929.
From 1940 until their abolition in 1974, there were only six more urban districts formed and a further fifty-six abolished, a net decrease of 50, bringing the total number of urban districts to 522.
^"Marlow UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Mablethorpe and Sutton UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Caterham UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Caterham and Warlingham UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Bude-Stratton UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Preesall UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^Annual Report of the Local Government Board. London: His Majesty's Stationery Office. 1901. p. 345. Retrieved 2 August 2022. The Pembroke (Llanstadwell and Neyland) Confirmation Order, 1900
^"Ellesmere Port and Whitby UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Ellesmere Port UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Foots Cray UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Sidcup UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Hayes and Harlington UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Merton and Morden UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Yiewsley and West Drayton UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Stratford and Wolverton UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Wolverton UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Bebington and Bromborough UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.
^"Bebington UD". A Vision of Britain through Time. GB Historical GIS / University of Portsmouth. Retrieved 8 November 2014.