Elections for the National Council are held every five years and the electoral system is based on the principle of proportional representation. The country is divided into nine provincial electoral districts according to the country’s nine federal states. An additional forty-three regional districts are contained in the initial nine. Every voter casts one ballot, in which the party of choice is indicated, as well as one candidate preference from the provincial and one from the regional district.In a three-stage votes counting procedure, regional votes are firstly counted, then provincial votes and, lastly, votes on the national party list. A party must win a seat at the regional level, in order to be able to have representatives elected on the provincial and national level. Regional and provincial seats are allocated using the Hare system, while MPs from the national party lists are elected through the d’Hondt method. The Austrian electoral system’s mechanism, especially through its third, national stage of allocating parliamentary seats, aims at ensuring that the number of seats won by a party will be as close as possible to the corresponding vote share.
A national threshold of 4% is at place in order for a party to be entitled to proportional representation at the national level. However, any individual seats won at the regional level are kept. In order for a candidate to be elected, she or he must win at least one sixth of her/his party votes or at least one half of the electoral quota, that is the number of valid ballots divided by the number of seats in a voting district. In total, about ninety parliamentary seats come from regional voting districts, sixty-five from provincial voting districts, and the remaining from the federal level.
Sources: Wikipedia.org, http://countrystudies.us/austria/116.htm