Each country has both a country calling code used to dial into a country and an international access code or international call prefix used to dial out of the country.

The International Telecommunications Union approved 00 as the general standard some time ago - that is, all countries should work towards unifying on this code, and this was also adopted by the European Union. However, due to technological constraints, this is not currently feasible in all countries.

Many member states also still use alternative dialing arrangements for calls to neighbouring countries.

The following countries and regions use an international call prefix other than 00:

• 0**0
  • Poland
• 00**
  • Algeria
  • Morocco
• 00xx
  • Brazil

('xx' represents two-digit carrier selection code 15, 21, 23, 31)

• 000
  • Kenya **Tanzania
  • Uganda
  • Zanzibar

(005, 006 and 007 are used for calls between the three countries, instead of 000 + country calling code.)

• 001
  • Hong Kong (also 0080, 009)
  • Indonesia (also 008)
  • Mongolia
  • Singapore (also 002, 008, 012, 013, 018, 019)
  • South Korea (also 002)
  • Thailand
• 0010
  • Bolivia (also 0011, 0012, 0013)
• 0011
  • Australia (also 0014, 0015, 0018)
• 002
  • Taiwan
  • Paraguay
• 005
  • Colombia (also 007, 009)
• 009
  • Nigeria
• 010
  • Japan
• 011
  • North American Numbering Plan Area
    • United States of America including Puerto Rico, U.S. Virgin Islands,Guam, Northern Mariana Islands and American Samoa
    • Canada
    • Anguilla
    • Antigua and Barbuda
    • Bahamas
    • Barbados
    • Barbuda
    • Bermuda
    • British Virgin Islands
    • Cayman Islands
    • Dominica
    • Dominican Republic
    • Grenada
    • Jamaica
    • Montserrat
    • Saint Kitts and Nevis
    • Saint Lucia
    • Saint Vincent and the Grenadines
    • Trinidad and Tobago
    • Turks and Caicos Islands
• 05
  • Papua New Guinea
• 09
  • South Africa
• 119
  • Cuba
• 15
  • Chad
• 19
  • Central African Republic
• 19**
  • Wallis and Futuna Islands
• 810
  • Azerbaijan
• 8**10 (written as "8~10")
  • Was a standard for the Soviet Union and so remains one for several post-Soviet countries:
    • Belarus
    • Georgia
    • Kazakhstan
    • Russia
    • Tajikistan
    • Turkmenistan
    • Ukraine
    • Uzbekistan
• 90
  • Burundi

Finland

In Finland, to encourage competition between telephone carriers international, a system of prefixes in the 99x was introduced in addition to the 00 prefix. For example, if the subscriber dials 990-1-234-567-7890 instead of 00-1-234-567-7890, the call will be routed via Sonera.

• 990
  • Sonera
• 991
  • Jippii
• 992
  • Tele2
• 994
  • Song
• 99500
  • Cubio
• 99588
  • Globetel
• 999
  • Elisa, Finnet

Notes

** — Await a second tone at this stage before continuing.