The requirement is for those who handed in their application documents to the police, embassy, consulate or Visa Application Centre 20 April 2018 or after.
The 24-years age limit was introduced for spouses and cohabitants on 1 January 2017. Now it has also been introduced for those who are applying for a residence permit for getting married in Norway.
It is the Norwegian parliament and government who have introduced this new requirement.
Read more about the new requirement and about who can be exempted.