Check-in for a flight abroad, there will be required credentials. The passport is the only valid credentials for a Dane. This also applies to in-check for flights between two Schengen countries.
Always check that your passport is valid and whether there should be a visa in the passport to your destination.
Each country have different rules for entry, so go to this link to the State department and get answers to all your questions about passports and visas.
The website of State Department
The name must match passport and plane ticket.
Please ensure that the full name on your passport is exactly the same name on the ticket. Otherwise you can be denied check-in.
If you have made a name change fx. in connection with marriage and you have not change your passport to the new name. Then you use your old name in the passport. It is your identity until you have changed your passport.
Citizen service with rules concerning passports
Children and passports
New rules on passports for children introduced 1 October 2004. Besides the increased demands for identity checks by passport-issuing is the significant change is that children – regardless of age – must have their own passports. Children who are enrolled in their parents’ passports before the first October 2004 may continue to travel without a passport, but a reissue of the passport, the child must have his own due to it is not possible now to get the child enrolled in their parents’ passports. Be aware that some countries require that children have their own passports. Some passports must have a certain validity period – in some cases six months – in addition to an exit date from that country.
You can read more about passports and passport-issuing at www.politi.dk
Visas and vaccinations
Some countries require that the traveler has a visa and have been vaccinated against certain diseases. Detailed information about passports, visas and vaccinations available on the website of the State department under the heading “Before the trip“