📋 Contents

📐 US Phone Number Format 🔢 What is an Area Code (NPA)? 📡 NXX — The Prefix 👤 Subscriber Number 📞 How to Make International Calls 🌍 International Dialing Codes

📐 Format of a US Phone Number: (NPA) NXX-XXXX

+1 Country Code
 
(NPA) Area Code
 
NXX Prefix
-
XXXX Subscriber

Example: +1 (212) 555-1234

🔢

NPA — Area Code

3-digit code identifying a geographic region. Developed by AT&T and Bell System in the 1940s. "NPA" stands for Numbering Plan Area. Some codes are reserved — 800 is toll-free, 900 is premium-rate.

📡

NXX — Prefix / Exchange

3-digit exchange prefix after the area code. Also called the NXX. Phone carriers reserve blocks of NXX codes within each area code. Not all prefixes are currently in use.

👤

XXXX — Subscriber Number

The final 4 digits uniquely identify a line. Each NXX prefix can hold 10,000 possible subscriber numbers (0000–9999), giving the US system capacity for over 1.6 billion phone numbers.

🏛️

NANPA — Who Manages It?

The North American Numbering Plan Administration (NANPA) governs area code allocation for the US, Canada, and Caribbean. They assign new area codes when existing ones fill up.

📅

Area Code History

Area codes were introduced in 1947. Direct long-distance dialing didn't begin until the early 1950s. The original plan had 86 area codes — today there are 380+ active codes and growing.

🚫

Reserved Codes

800/888/877/866/855/844/833 — Toll-free. 900 — Premium rate (caller pays). 911 — Emergency services. 411 — Directory assistance. 211/311/511/711 — Special services.

📞 How to Make International Calls

To call internationally, dial in this order:

International Dialing Code (exit your country)
+
Country Code (enter destination)
+
Phone Number (local number)
Example: Calling a US number from France: dial 00 (France exit code) + 1 (US country code) + 212-555-1234

The "+" symbol in a published number (e.g. +1-212-555-1234) replaces the international dialing code. On mobile phones, you can often press and hold "0" to enter "+".

🌍 International Dialing Codes & Country Codes 128 Countries

Scroll horizontally on mobile. Data sourced from ITU-T.

Country Country Code Int'l Dial Code National Prefix UTC Offset
Afghanistan +93 00 0 +4:30
Albania +355 00 0 +1/+2
Algeria +213 00 0 +1
American Samoa +1 011 1 -11
Andorra +376 00 — +1/+2
Angola +244 00 0 +1
Argentina +54 00 0 -3
Armenia +374 00 0 +4
Australia +61 0011 0 +10/+11
Austria +43 00 0 +1/+2
Azerbaijan +994 00 0 +4
Bahamas +1 011 1 -5/-4
Bahrain +973 00 — +3
Bangladesh +880 00 0 +6
Barbados +1 011 1 -4
Belarus +375 810 8 +3
Belgium +32 00 0 +1/+2
Belize +501 00 — -6
Bolivia +591 00 0 -4
Brazil +55 00 0 -3/-2
Bulgaria +359 00 0 +2/+3
Cambodia +855 001/007 0 +7
Cameroon +237 00 — +1
Canada +1 011 1 -5/-4
Chile +56 1YZ0 1YZ -4/-3
China +86 00 0 +8
Colombia +57 009 09 -5
Costa Rica +506 00 — -6
Croatia +385 00 0 +1/+2
Cuba +53 119 0 -5/-4
Cyprus +357 00 — +2/+3
Czech Republic +420 00 — +1/+2
Denmark +45 00 — +1/+2
Dominican Republic +1 011 1 -4
Ecuador +593 00 0 -5
Egypt +20 00 0 +2
Ethiopia +251 00 0 +3
Finland +358 00 0 +2/+3
France +33 00 0 +1/+2
Georgia +995 8 8 +4
Germany +49 00 0 +1/+2
Ghana +233 00 0 UTC
Greece +30 00 0 +2/+3
Guam +1 011 1 +10
Guatemala +502 00 — -6
Haiti +509 00 — -5/-4
Honduras +504 00 — -6
Hong Kong +852 001 — +8
Hungary +36 00 06 +1/+2
Iceland +354 00 — UTC
India +91 00 0 +5:30
Indonesia +62 001/008 0 +7
Iran +98 00 0 +3:30
Iraq +964 00 0 +3
Ireland +353 00 0 UTC/+1
Israel +972 00 0 +2/+3
Italy +39 00 — +1/+2
Jamaica +1 011 1 -5
Japan +81 010 0 +9
Jordan +962 00 0 +2/+3
Kazakhstan +7 810 8 +6
Kenya +254 000 0 +3
Korea (South) +82 001 0 +9
Kuwait +965 00 — +3
Latvia +371 00 — +2/+3
Lebanon +961 00 0 +2/+3
Lithuania +370 00 0 +2/+3
Luxembourg +352 00 — +1/+2
Malaysia +60 00 0 +8
Malta +356 00 — +1/+2
Mexico +52 00 01 -6/-5
Moldova +373 00 0 +2/+3
Monaco +377 00 — +1/+2
Mongolia +976 001 0 +8
Montenegro +382 00 0 +1/+2
Morocco +212 00 0 UTC/+1
Mozambique +258 00 — +2
Myanmar +95 00 0 +6:30
Nepal +977 00 0 +5:45
Netherlands +31 00 0 +1/+2
New Zealand +64 00 0 +12/+13
Nicaragua +505 00 — -6
Nigeria +234 009 0 +1
North Korea +850 00 0 +9
Norway +47 00 — +1/+2
Oman +968 00 — +4
Pakistan +92 00 0 +5
Panama +507 00 — -5
Paraguay +595 00 0 -4/-3
Peru +51 00 0 -5
Philippines +63 00 0 +8
Poland +48 00 0 +1/+2
Portugal +351 00 — UTC/+1
Puerto Rico +1 011 1 -4
Qatar +974 00 — +3
Romania +40 00 0 +2/+3
Russia +7 810 8 +3 to +12
Saudi Arabia +966 00 0 +3
Serbia +381 00 0 +1/+2
Singapore +65 001/008 — +8
Slovakia +421 00 0 +1/+2
Slovenia +386 00 0 +1/+2
South Africa +27 00 0 +2
Spain +34 00 — +1/+2
Sri Lanka +94 00 0 +5:30
Sweden +46 00 0 +1/+2
Switzerland +41 00 0 +1/+2
Syria +963 00 0 +2/+3
Taiwan +886 002 0 +8
Tajikistan +992 810 8 +5
Tanzania +255 000 0 +3
Thailand +66 001 0 +7
Trinidad and Tobago +1 011 1 -4
Tunisia +216 00 — +1
Turkey +90 00 0 +2/+3
Turkmenistan +993 810 8 +5
Uganda +256 000 0 +3
Ukraine +380 00 0 +2/+3
United Arab Emirates +971 00 0 +4
United Kingdom +44 00 0 UTC/+1
United States +1 011 1 -5/-4
Uruguay +598 00 0 -3
Uzbekistan +998 810 8 +5
Venezuela +58 00 0 -4:30
Vietnam +84 00 0 +7
Yemen +967 00 0 +3
Zambia +260 00 0 +2
Zimbabwe +263 00 0 +2