You will need a valid driver’s license along with an ID or passport. Those with a license in a non-Roman alphabet, like Japanese or Greek, will also need an international driving permit.
One-way rentals between SIXT branches in Croatia are allowed, depending on the car category. It is also possible to do a one-way rental to select countries from Croatia. An additional fee may apply.
In general, the minimum age for car rental in Zagreb is 18. However, some car categories require renters to be 25 with a valid license for 2 years. An underage driver fee applies to those under 22 years of age.