After the break-up of Czechoslovakia into the Czech Republic and Slovakia, the country code 42 was used by both countries for another four years and changed eventually to 420 for the Czech Republic, and 421 for Slovakia.
The next one to three digits after the country code give information about the number's location.
In 2002 the area codes were standardised and issued as follows:
2 - Prague
31, 32 - Central Bohemian Region
35 - Karlovy Vary Region
37 - Plzeň Region
38, 39 - South Bohemian Region
41, 47 - Ústí nad Labem Region
46 - Pardubice Region
48 - Liberec Region
49 - Hradec Králové Region
51, 53, 54 - South Moravian Region
55, 59 - Moravian-Silesian Region
56 - Vysočina Region
57 - Zlín Region
58 - Olomouc Region
Mobile prefixes are either two or three digits, between the range of 602 to 608 and 72 to 79. However since cell phone numbers can be kept when you change your provider, it is not possible to derive the network provider from the prefix number. If you call a mobile number that is no longer registered with the original provider you will hear a short message before you are put through. This way you know whether you have to pay more for the call.
112 - general emergency number
155 - medical emergencies
150 - fire department
158 - police
154 - towing service
1230,1240 - emergency road service
In addition there is a special number in case you can't or don't want to drive home after going out. You just need to call 00420 604 70 70 70 and you and your car will be taken home.
800 - free of charge
844 - only charges tariff for local call, if dialed from a fixed line
90 - generally high tariff
There are many public payphones in the Czech Republic. There are two types; those accepting coins, and those accepting telephone cards. Telephone cards can be bought at news stands, post offices, department stores etc. Using public payphones is convenient if you are not staying in the Czech Republic for very long. They are very expensive however if you make international calls.
To make international calls from the Czech Republic you have to dial 00, followed by the appropriate country code. Since international calls are usually very expensive there is a huge number of different calling cards available. These allow you to make relatively cheap phone calls to a prespecified country.