Under DSB's 'Good trains for everyone' plan ('Gode tog til alle'), the intent of the IC4 project was to replace several types of outdated rolling stock.

On 27 August 2007, another test train entered regional passenger service between Aarhus and Fredericia in eastern Jutland.

The IC4's first long-distance run, from Aalborg to Copenhagen, took place on 7 August 2008, while the train finally received approval for regular service with multiple connected trainsets on 9 November 2010.

[3] The 82nd and final unit (MG 5683) was delivered to DSB in September 2013, and as of 2015, IC4 trains are in regular operation on the Aarhus-Copenhagen, Aarhus-Aalborg, Aarhus-Esbjerg, Odense-Fredericia and Copenhagen-Holbæk-Kalundborg connections.

[1] Each train set consists of four articulated cars with a total length of 86 m (282 ft 2 in), and is capable of seating 204 people.

The train interior features natural materials consistent with Scandinavia's design tradition, an audio/video information system with seat reservation displays, and a lounge area.

The Danish Minister of Traffic and Energy is routinely required to submit progress updates to parliament, and DSB's choice of a heavily customised train is often criticised as being the major reason for the delays.

[8] Along with the (partial) fulfilment of the ultimatum, DSB also announced it had reached an agreement with AnsaldoBreda concerning delivery of the remaining trainsets.

[7] DSB, in cooperation with Deutsche Bahn, has started using German tilting ICE-TD diesel trains to and from Germany.

[3] At the end April 2011, DSB's director, Frank Olesen, stated that further economic sanctions against AnsaldoBreda were likely to be imposed as a result of continuing problems with the quality of the trains delivered.

In September 2014 an investigation by the Danish Department of Transport was launched to find whether it was more economical to have the delivered trains scrapped or have them rebuilt for slower regional traffic.

[21] Schrøder also stated that the overall reliability of the fleet had been improved by the withdrawing of a number of particularly problematic units, which he referred to as "Monday models" and "hangar queens".

[21] In July 2020 DSB offered 11 of the withdrawn "hangar queen" units for sale through a broker in England, describing them as being "in very good working order".

However, he also noted that all 11 units had been continuously maintained since being withdrawn, and that they were being sold because the increasing reliability of the main IC4 fleet had made them redundant.

[22] On 2 June 2022, Danish news magazine Ingeniøren published an article claiming that DSB has agreed to sell the entire fleet of 74 IC4 units – not just the 11 previously offered for sale – to an undisclosed foreign buyer.

The sale is believed to involve an initial delivery of 14 units, with the remainder of the fleet to follow as it is phased out of operation with DSB.

[23] The exact timing will depend on the progress of DSB's order for the Alstom Coradia Stream electric multiple-unit trains that will replace the IC4 fleet; as of May 2022 the first of the new units is expected to enter service in mid-2025.