International Dialing Code

International telephone dialing prefix assigned by ITU (International Telecommunication Union). Format: + followed by 1-3 digits (e.g., +1, +44, +971). Extracted from REST Countries API IDD field which contains root (e.g., "+1") and suffixes (area codes). For countries with a single short suffix (1-2 digits), it is concatenated to the root to form the full country code. For countries with many suffixes, they represent area codes within the country.

IDD codes are essential for making international calls, understanding phone number formats, and verifying phone numbers in online forms. Travelers need to know their destination's code to call hotels, restaurants, or local contacts. Shared codes indicate geographic/historical ties (e.g., +1 for USA/Canada/Caribbean, +7 for Russia/Kazakhstan). Some codes are highly recognizable (+44 UK, +33 France), while others are less known, causing confusion.

Single-digit codes: +1, +7 (rare, assigned early) - +1: USA, Canada, and 25+ Caribbean/Atlantic islands (NANP - North American Numbering Plan) - +7: Russia, Kazakhstan Two-digit codes: +20 to +99 (most common) - Examples: +20 Egypt, +27 South Africa, +30 Greece, +33 France, +39 Italy, +44 UK, +49 Germany, +52 Mexico, +55 Brazil, +61 Australia, +81 Japan, +86 China, +91 India Three-digit codes: +212 to +998 (smaller countries, later assignments) - Examples: +212 Morocco, +234 Nigeria, +351 Portugal, +420 Czech Republic, +966 Saudi Arabia, +971 UAE, +972 Israel Shared codes (countries share same IDD code, use area codes to distinguish): - +1: All of North America and Caribbean (23 countries) - USA +1-202 (DC), Canada +1-416 (Toronto), Jamaica +1-876, etc. - +44: UK territories - Jersey +44-1534, Guernsey +44-1481, Isle of Man +44-1624 - +590: Guadeloupe, Saint Barthélemy, Saint Martin (France) Special cases: - +800: International Freephone Service - +870: Inmarsat satellite service - +882: International Networks (VSAT, etc.) - +888: Disaster relief hotlines

Coverage: 217 countries Update frequency: Static (ITU changes rare, usually with new countries) Source: REST Countries API (based on ITU E.164 assignments) Limitations: Does not include area codes or city codes (only country-level code). Some territories share parent country codes (e.g., French overseas territories use +590, +594, +596, +262 - different codes despite being French). Mobile vs landline prefixes not captured. VoIP and virtual numbers bypass geographic codes. Emergency numbers (e.g., 112 in EU, 911 in US) not included. Calling costs vary drastically - same code doesn't mean same rates.