Denmark is divided into five regions, which contain 98 municipalities ( , sing.: ). The Capital Region has 29 municipalities, Southern Denmark 22, Central Denmark 19, Zealand 17 and North Denmark 11.
This structure was established per an administrative reform (Danish: Strukturreformen; English: (The) Structural Reform) of the public sector of Denmark, effective 26 June 2005 (council elections 15 November 2005), which abolished the 13 counties (; singular ) and created five regions (; singular ) which unlike the counties (1970–2006) (Danish (singular) amtskommune ) are not municipalities. The 270 municipalities were consolidated into 98 larger units, most of which have at least 20,000 inhabitants.
67 of the present municipalities are mergers as a result of the administrative reform, with Ærø being allowed to merge already on 1 January 2006, and one municipality, Bornholm Regional Municipality, being a merger from 1 January 2003, before the reform, that is 68 merged municipalities in all. 238 municipalities were merged 1 January 2007 to form 66 municipalities for a total of 245 merged municipalities in 2003, 2006, and 2007. The 30 remaining municipalities have not merged.
Before the merger on Bornholm there were 275 municipalities and 14 counties. Two sui generis municipalities, namely Copenhagen and Frederiksberg, were never a part of a county, but were counties in their own right.
Many of the responsibilities of the former counties were taken over by the 98 municipalities. With the increased responsibilities, the income tax rate that each of the 98 municipalities levies was raised by three percentage points on 1 January 2007. This tax had once been a part of the tax levied by the former counties.
The archipelago of Ertholmene is not part of any municipality, but is administered by the Ministry of Defence.
The average land area of a Danish municipality is 432.59 km2, 167.08 square miles. The area given in each article about municipalities – and regions – is the total area of land and water, of which the latter can make up a large part for instance in Halsnæs Municipality.
Legal foundation of municipalities
The Constitution of Denmark states: "Article 82. The right of municipalities to manage their own affairs independently, under State supervision, shall be laid down by statute."
Councillors
2,522 municipal councillors (and 205 regional councillors) were elected on Tuesday 15 November 2005, being the first councils elected since the new reform. In 1997 there were 4,685 municipal and 374 county councillors in the then-275 municipalities and 14 counties. As an example of the reduction in the number of councillors, Bornholm in the 1970s and 1980s had a total of 122 councillors (from 1999:89) in five municipalities and one county (18 county councillors in the 1990s [from 1999: 15]). After the merger on 1 January 2003, of the five municipalities and the county, there was one single municipal council with 27 municipal councillors. They were reduced to 23 from 1 January 2018. After 1 January 2007, when Bornholm Regional Municipality lost its (short-lived – four years: 2003 until 2006) county privileges, there has been talk of a reduction to 19 municipal councillors, the guidelines for a municipality with over 20,000 inhabitants being a maximum of 31 and minimum of 19 municipal councillors and the guidelines for a municipality with less than 20,000 inhabitants being a maximum of 31 and minimum of 9 municipal councillors. These guidelines replaced the old guidelines with the council elections in 2005 after the laws initiating the structural reform were passed in parliament. Many newly formed municipalities have chosen to have a maximum number of councillors so that all parts of the new municipalities and the small political parties have a chance of representation in the new councils: Copenhagen Municipality has 55 municipal councillors on its council, and populous municipalities such as Århus and Aalborg have 31 each, and Odense and Frederiksberg (Frb from 1 Jan 2022) have 29. Gentofte (from 17 to 19 councillors in elections 2009), Glostrup (from 17 to 19 cllrs in 2009), Hørsholm (from 15 to 19 cllrs in 2005), Ishøj (from 17 to 19 cllrs in 2009), Solrød (from 15 to 19 cllrs in 2009), and Tårnby (from 17 to 19 cllrs in 2009) are examples of municipalities that have increased the number of councillors because of the new guidelines.
Council elections are held on the third Tuesday of November every four years. The previous elections were held on 16 November 2021.