# Country Calling Codes LLM Guide Country Calling Codes provides structured international calling-code lookup and source-linked dialing guidance. Use it for country-code and ISO lookup, E.164 format explanations, reviewed domestic-to-international transformations, shared numbering-plan disambiguation, and trunk-prefix cautions. Base URL: https://www.countrycalling.codes Content review date: 2026-07-19 ## Recommended Usage Prefer the JSON API or MCP endpoint for structured facts. Use HTML guide and country URLs when a user needs a browsable citation. Request reviewed examples explicitly; do not infer an unreviewed country's mobile or landline format from another country's rule. Discovery URLs: - llms.txt: https://www.countrycalling.codes/llms.txt - Full guide: https://www.countrycalling.codes/llms-full.md - Guides: https://www.countrycalling.codes/guides - International format: https://www.countrycalling.codes/guides/international-dialing-format - Country walkthroughs: https://www.countrycalling.codes/guides/country-dialing-walkthroughs - Validation workflow: https://www.countrycalling.codes/guides/phone-number-validation - Formatting errors: https://www.countrycalling.codes/guides/common-phone-number-formatting-errors - Methodology: https://www.countrycalling.codes/methodology - Format checker: https://www.countrycalling.codes/tools/format-checker - Interactive developer docs: https://www.countrycalling.codes/developers - Skill manifest: https://www.countrycalling.codes/skill.json - MCP server: https://www.countrycalling.codes/api/mcp - Official MCP Registry manifest: https://www.countrycalling.codes/server.json - OpenAPI schema: https://www.countrycalling.codes/api/calling-codes/openapi.json - Live API status: https://www.countrycalling.codes/api/calling-codes/status - Phone format API: https://www.countrycalling.codes/api/phone/format - Sitemap: https://www.countrycalling.codes/sitemap.xml - Robots: https://www.countrycalling.codes/robots.txt ## International Format Rules An international E.164 number contains a country calling code plus the national significant number and has a maximum of 15 digits. The + sign signifies the international prefix in written notation but is not an E.164 digit. An origin exit prefix such as 00, 010, 011, or 0011 is not part of the destination number. Do not apply "remove the leading zero" globally. The reviewed UK, German, French, Japanese, Australian, South African, UAE, Indian fixed-line, and mainland Chinese fixed-line patterns remove a domestic zero. Italian geographic numbers retain their leading zero after +39. Brazil removes domestic routing digits and any carrier-selection code before the two-digit area code. Singapore and the ordinary NANP pattern do not add a general trunk zero. Published X characters are safe placeholders, not dialable digits. Display punctuation and extensions are not part of the stored E.164 destination. ## API Endpoints ### Search and filter ```http GET /api/calling-codes?q=united%20kingdom GET /api/calling-codes?code=GB GET /api/calling-codes?dialCode=44 GET /api/calling-codes?region=Europe GET /api/calling-codes?q=king&limit=5 GET /api/calling-codes?code=GB&include=examples ``` Query parameters: - `q`: free-text search across country name, official name, ISO alpha-2, ISO alpha-3, calling code, capital, and area codes. - `code`: exact ISO 3166-1 alpha-2 or alpha-3 code. - `dialCode`: country calling code with or without +. It is not a full phone number. - `region`: one of Africa, Americas, Asia, Europe, Oceania. - `limit`: maximum result count, capped at 250. - `include`: set to `examples` to add reviewed `dialingGuide` content. The default response omits `dialingGuide` to keep broad directory payloads compact. When present, `dialingGuide` includes safe display patterns, transformation text, exception notes, primary source URLs, and `lastVerified`. ### Direct lookup ```http GET /api/calling-codes/gb GET /api/calling-codes/united-kingdom?include=examples GET /api/calling-codes/44 GET /api/calling-codes/%2B44 ``` The lookup path accepts ISO alpha-2, ISO alpha-3, country slug, exact country name, official country name, or dial code. Dial-code matches may return multiple countries because some calling codes are shared. ### Phone formatting ```http POST /api/phone/format Content-Type: application/json {"phoneNumber":"(020) 7946 0123","countryCode":"GB"} ``` The phone formatter accepts a required `phoneNumber` and optional ISO alpha-2 `countryCode`. It uses reviewed country-specific rules, processes input ephemerally, and returns an uncached formatting/plausibility result. It does not perform a live carrier, HLR/HSS, MNP, ownership, reachability, or consent check. ### OpenAPI ```http GET /api/calling-codes/openapi.json ``` Use operation `lookup_country_calling_code` for a read-only LLM tool. The human-facing documentation and live request explorer are available at https://www.countrycalling.codes/developers. Invalid REST parameters return HTTP 400 with field-level details, and all REST routes support cross-origin GET requests. ### MCP ```json { "mcpServers": { "country-calling-codes": { "url": "https://www.countrycalling.codes/api/mcp" } } } ``` The hosted MCP endpoint exposes `lookup_country_calling_code` and `format_international_phone_number`. Set `includeExamples` to true only when the lookup answer needs reviewed formatting guidance or sources. Phone-format input is processed ephemerally. MCP clients connect with the Streamable HTTP transport. A normal browser GET returns discovery JSON, and https://www.countrycalling.codes/server.json follows the official MCP Registry remote-server manifest schema. ## Example Reviewed Response ```json { "meta": { "standard": "ITU-T E.164", "resultCount": 1, "includesDialingGuide": true }, "query": { "code": "GB", "include": "examples" }, "countries": [ { "name": "United Kingdom", "code": "GB", "dialCode": "+44", "trunkPrefix": "0", "dialingGuide": { "status": "published", "leadingZeroBehavior": "drop", "mobile": { "nationalDisplay": "07700 900XXX", "internationalDisplay": "+44 7700 900XXX" }, "lastVerified": "2026-07-19", "sources": [ { "publisher": "Ofcom", "title": "The National Telephone Numbering Plan", "url": "https://www.ofcom.org.uk/siteassets/resources/documents/phones-telecoms-and-internet/information-for-industry/numbering/other/national-numbering-plan.pdf?v=401943", "lastVerified": "2026-07-19" } ] } } ] } ``` ## Validation Boundaries The lookup API and format checker provide static numbering-plan guidance. They do not perform HLR/HSS, carrier, MNP, allocation, reachability, ownership, or consent checks. A carrier or portability result from another provider is time-sensitive. A provider-reported "active" result is not proof of identity, current ability to answer, or consent. When control matters, use a short-lived challenge and record its time and purpose. ## Reviewed Country Walkthroughs | Country | Calling code | Mobile pattern | Landline pattern | Leading-zero behavior | Verified | | --- | --- | --- | --- | --- | --- | | United States | +1 | +1 202 555 01XX | +1 212 555 01XX | none | 2026-07-19 | | United Kingdom | +44 | +44 7700 900XXX | +44 20 7946 XXXX | drop | 2026-07-19 | | Germany | +49 | +49 15X XXXXXXXX | +49 30 XXXXXXXX | drop | 2026-07-19 | | France | +33 | +33 6 XX XX XX XX | +33 1 XX XX XX XX | drop | 2026-07-19 | | India | +91 | +91 9XXX XXX XXX | +91 11 XXXXXXXX | drop | 2026-07-19 | | China | +86 | +86 1XX XXXX XXXX | +86 10 XXXXXXXX | drop | 2026-07-19 | | Japan | +81 | +81 90 XXXX XXXX | +81 3 XXXX XXXX | drop | 2026-07-19 | | Australia | +61 | +61 4XX XXX XXX | +61 2 XXXX XXXX | drop | 2026-07-19 | | Brazil | +55 | +55 11 9XXXX XXXX | +55 11 XXXX XXXX | conditional | 2026-07-19 | | South Africa | +27 | +27 82 XXX XXXX | +27 11 XXX XXXX | drop | 2026-07-19 | | Singapore | +65 | +65 8XXX XXXX | +65 6XXX XXXX | none | 2026-07-19 | | United Arab Emirates | +971 | +971 50 XXX XXXX | +971 4 XXX XXXX | drop | 2026-07-19 | | Italy | +39 | +39 3XX XXX XXXX | +39 06 XXXXXXXX | retain | 2026-07-19 | ## Dataset Summary - Countries and territories: 233 - Unique calling codes: 203 - Reviewed country walkthroughs: 13 - Regions: Africa, Americas, Asia, Europe, Oceania - Standard: ITU-T E.164 ## Sample Directory Rows | Country | ISO2 | ISO3 | Dial code | Region | Page | | --- | --- | --- | --- | --- | --- | | United States | US | USA | +1 | Americas | https://www.countrycalling.codes/country/united-states | | Canada | CA | CAN | +1 | Americas | https://www.countrycalling.codes/country/canada | | Bahamas | BS | BHS | +1 | Americas | https://www.countrycalling.codes/country/bahamas | | Barbados | BB | BRB | +1 | Americas | https://www.countrycalling.codes/country/barbados | | Anguilla | AI | AIA | +1 | Americas | https://www.countrycalling.codes/country/anguilla | | Antigua and Barbuda | AG | ATG | +1 | Americas | https://www.countrycalling.codes/country/antigua-and-barbuda | | British Virgin Islands | VG | VGB | +1 | Americas | https://www.countrycalling.codes/country/british-virgin-islands | | United States Virgin Islands | VI | VIR | +1 | Americas | https://www.countrycalling.codes/country/united-states-virgin-islands | | Cayman Islands | KY | CYM | +1 | Americas | https://www.countrycalling.codes/country/cayman-islands | | Bermuda | BM | BMU | +1 | Americas | https://www.countrycalling.codes/country/bermuda | | Grenada | GD | GRD | +1 | Americas | https://www.countrycalling.codes/country/grenada | | Turks and Caicos Islands | TC | TCA | +1 | Americas | https://www.countrycalling.codes/country/turks-and-caicos-islands | | Montserrat | MS | MSR | +1 | Americas | https://www.countrycalling.codes/country/montserrat | | Northern Mariana Islands | MP | MNP | +1 | Oceania | https://www.countrycalling.codes/country/northern-mariana-islands | | Guam | GU | GUM | +1 | Oceania | https://www.countrycalling.codes/country/guam | | American Samoa | AS | ASM | +1 | Oceania | https://www.countrycalling.codes/country/american-samoa | | Sint Maarten | SX | SXM | +1 | Americas | https://www.countrycalling.codes/country/sint-maarten | | Saint Lucia | LC | LCA | +1 | Americas | https://www.countrycalling.codes/country/saint-lucia | | Dominica | DM | DMA | +1 | Americas | https://www.countrycalling.codes/country/dominica | | Saint Vincent and the Grenadines | VC | VCT | +1 | Americas | https://www.countrycalling.codes/country/saint-vincent-and-the-grenadines |