Danish women are faced with being called for 11 months of military service when it reaches 18 months after the changes to the law came into effect.
Under the new rules passed by Danish parliament, women are to join teenage men in a lottery system that could require them to take on a period of conscription.
This change has been brought about as NATO countries promote defence spending amid growing security concerns in Europe.
Previously, women were allowed to participate in military service when they turned 18, but voluntarily.
Starting Tuesday, both men and women, who will be 18, will need to register to receive a rating for potential military service. Volunteers are first hired, with the remaining numbers being made up through the lottery system.
The change also raises the teenager’s draft season from four to eleven months.
Approximately 4,700 Danish men and women performed brief military service in 2024. Approximately 24% of these are female volunteers. The new rules on conscription are expected to rise to 6,500 for all military service annually by 2033.
Denmark follows the examples of neighbouring Sweden and Norway, both of which have in recent years brought conscription for women.
In March, the government announced a rise of 40.5 billion Danish crowns (£4.3 billion, $5.9 billion) over the next five years to achieve NATO goals.
Currently, there are approximately 9,000 professional staff working in the Danish military.
Colonel Kenneth Strom, director of the Danish military’s draft program, said the change was “based on political decisions and political agreements by political parties.”
He added: “And obviously it’s based on the current security situation to gain more combat power and has the skills needed by the Army, Navy, Air Force, or even special operations forces.”
Katlin, a current volunteer with the Danish military, told Reuters.
“I think that’s a positive change.”
