Post Danmark had taken over the mail delivery concession (Danish: befordringspligt) of its predecessor, the governmental department Postvæsenet, which was established in 1624.

In 2009, it was merged with the Swedish Posten AB to form PostNord, a joint postal service company between Denmark and Sweden.

As of 2007, Post Danmark employed about 21,000 people, and delivered approximately a billion letters and 37 million parcels every year.

On 1 April 2008 Post Danmark announced its intention to merge with its Swedish counterpart, Posten AB,[4] to realise greater economies of scale and postal synergies.

The combined company post-merger had an annual revenue of approximately 45 billion Swedish krona and employed more than 50,000 people.