List of country calling codes

Structure and organization

The international telephone numbering plan follows the ITU-T E.164 recommendation. A complete dialled sequence may include an international prefix, a country calling code (one to three digits), and the national significant number. The maximum length for an E.164 number is 15 digits, including the country code. Many countries also use a trunk prefix (commonly 0) for domestic long-distance calls.

• International prefix — the digits dialled to begin an international call (varies by country, e.g. 00 or 011).
• Country calling code — one to three digits assigned by the ITU.
• National significant number — the subscriber number including any area or mobile codes.

Regional grouping and examples

Codes are broadly grouped by their leading digit for geographical convenience. For example, the North American Numbering Plan uses +1 for the United States, Canada and several Caribbean nations; the United Kingdom is +44; Germany +49; China +86; India +91; Japan +81. In addition to geographic codes there are non‑geographic assignments used for international services such as universal toll‑free numbers.

History and governance

Country codes are allocated and coordinated by the International Telecommunication Union (ITU). Assignments have evolved with political and technical changes: new codes can be created when states gain independence or when numbering plans are reorganized. The ITU maintains the international registry and technical standards that ensure interoperability between national networks.

Dialing practices and practical notes

From many mobile phones the plus sign (+) is accepted as a shorthand for the international prefix, letting users dial a number with its country code from anywhere. Domestic dialing rules differ: some countries require dialing a trunk prefix for calls outside a local area, others use closed numbering plans that always require the full national number. Shared or overlay arrangements and changes to numbering plans can affect subscribers and require updates to directories and systems.

Notable distinctions

• Some territories share a country code with a larger neighbour or an international numbering plan (for example, several Caribbean islands under +1).
• Non‑geographic and service codes exist for special international services and can be subject to different routing rules.
• Emergency numbers and short codes are separate from country calling codes and are handled within national networks.