The postal code consists of five digits, usually written with a space in the form XXX XX. The first digit indicates a region (i.e. regions of Czechoslovakia as of the time when the PSČ system was put into use, hence some differences from the current administrative divisions):
1 - the capital of the Czech Republic, Prague (second digit represents one of 10 Prague districts, so e.g. 160 00 is the main post office in Prague 6 - Dejvice).
2 - central Bohemia (272 01 Kladno, 280 01 Kolín). Numbers 200 00 - 249 99 are reserved for internal needs of the postal system itself and are not assigned to any region. The Prague central distribution post office uses 225 00.
8 - the capital of Slovakia, Bratislava. The second digit represents one of the five districts of Bratislava. The codes 860 01-899 99 are not assigned to any region and serve for internal purposes of the postal system.
Addresses with large mail traffic can get their own postal code.
Format
When writing the address, the postal code is put in front of the town name; when typed or printed, 1 space separates the leading 3 digits from the trailing 2 digits, and 2 spaces separate the postal code from the town name, e.g.:
Na Příkopě 28
115 03Praha 1
International mail
On postal items being sent from abroad it is recommended to prepend the postal code with the ISO 3166-1 two-letter code of the country and a dash:
Na Příkopě 28
CZ-115 03Praha 1
the Czech Republic
On envelopes and postcards there are usually five rectangular boxes below the address field for the postal code digits.
