Country Calling Codes — International Dialing Prefixes by Country

How Calling Codes Work

International calling codes (also called dialing prefixes or country codes for telephony) are assigned by the International Telecommunication Union (ITU) under the E.164 numbering plan. They are distinct from ISO 3166 country codes but are commonly displayed alongside them.

Zone Assignments

The ITU assigns calling code zones geographically:

Zone	Region	Examples
+1	North America (NANP)	USA, Canada, Caribbean
+2x	Africa	+20 Egypt, +27 South Africa, +234 Nigeria
+3x	Europe	+33 France, +34 Spain, +49 Germany
+4x	Europe (continued)	+44 UK, +46 Sweden, +48 Poland
+5x	Central/South America	+52 Mexico, +55 Brazil, +56 Chile
+6x	Southeast Asia & Oceania	+61 Australia, +62 Indonesia, +81 Japan
+7	Russia & Kazakhstan	+7 (both countries)
+8x	East Asia	+82 S. Korea, +86 China, +81 Japan
+9x	West/Central/South Asia	+91 India, +92 Pakistan, +98 Iran

The E.164 Format

The E.164 standard defines the full international phone number format:

+[country code][subscriber number]
Maximum 15 digits total (excluding the +)

Examples:

• +1 212 555 1234 (US - New York)
• +44 20 7946 0958 (UK - London)
• +81 3 1234 5678 (Japan - Tokyo)

Shared Calling Codes

Several countries share the same calling code:

Code	Countries
+1	US, Canada, and 20+ Caribbean nations (different area codes)
+7	Russia, Kazakhstan
+44	UK, Guernsey, Jersey, Isle of Man
+39	Italy, Vatican City

Mobile-Only Codes

Some countries have separate mobile prefixes that are part of the subscriber number, not the country code. For example, UK mobiles start with +44 7xxx, while landlines start with +44 20xx (London) or +44 1xxx.

Implementation Tips

When storing phone numbers in a database:

1. Store in E.164 format: +14155551234
2. Validate with a library (libphonenumber)
3. Display with formatting: +1 (415) 555-1234
4. Index on the country code for fast lookups