In Hungary the standard lengths for area codes is one (Budapest only) and two (rest of areas) digits and 7 or 8 (cell phone numbers beginning with 20, 30 and 70 and corporate network numbers starting with 71) for subscribers' numbers in Hungary.
Calls within local areas can be made by dialling the number without the area code, such as 123-4567 in Budapest or 123-456 in other areas. However, this is not permitted in mobile phone networks.
Domestic calls to all other area codes must be preceded with 06 + area code. For example, a call from Budapest to Monor (area code 29) would be made as 06 29 123-456 and a call from Monor to Budapest (area code 1) would be made as 06 1 234-5678. When using mobile phones, the international format can be used instead: +36 1 234-5678.
Calls to international destinations are in the format 00 + country code + number. On mobile phones, + can be used instead of 00.
Note: After April 1, 2004, the phone numbers can be carried from network to network. That means any of the previous codes can refer to any mobile provider.