Austria's postal codes typically consist of four digits, with the initial digit often representing one of Austria's nine federal states, providing a broad regional categorization. However, exceptions exist where certain regions or municipalities may share the same initial digit despite belonging to different states, or where specific geographic or administrative factors may result in variations to this pattern. The subsequent digits refine the geographical scope further, identifying specific districts and municipalities within the respective state. These codes are instrumental in facilitating efficient mail delivery, enabling precise localization of addresses across Austria's diverse landscape.

The first indicates the state:
1xxx: Vienna
2xxx: Lower Austria (east of Vienna)
3xxx: Lower Austria (west of Vienna)
4xxx: Upper Austria
5xxx: Salzburg and west Upper Austria
6xxx: Tyrol and Vorarlberg (without East Tyrol)
7xxx: Burgenland
8xxx: Styria
9xxx: Carinthia and East Tyrol