Nina Moland Andersen, sales and marketing manager at Color Line, said bookings had increased five-fold since Norway said it would drop the six-day requirement from this Saturday.
“We have had a great demand from people who are booking trips with fewer nights,” she told Norway's state broadcaster NRK.
Fjord Line also said sales of seats on its Kristiansand to Hirtshals ferry had leapt by a fifth.
Denmark's justice ministry said in a statement on Wednesday that from Saturday the whole of Norway would be classed along with Schleswig-Holstein in Germany and Skåne, Halland and Blekinge in Sweden as a “borderland”.
This means tourists from Norway will not have to show that they have booked accomodation for six days in order to enter Denmark.