Two-Letter Abbreviations for Countries (ISO 3166-1 Alpha-2 Codes) Explained

TL;DR: A two-letter country code is an ISO 3166-1 alpha-2 code, a two-character identifier assigned by the ISO 3166 Maintenance Agency to represent a country, dependent territory, or special area of geographic interest. There are 249 currently assigned codes. US is the United States, DE is Germany, JP is Japan. The full list is below, along with the exceptions that break integrations.

Updated 26 August 2026. Verified against ISO 3166-1 as maintained by the ISO 3166/MA. 249 assigned codes.

01What Is a Two-Letter Country Code?

A two-letter country code is a two-character identifier defined by ISO 3166-1, published by the International Organization for Standardization. The formal name is ISO 3166-1 alpha-2.

Codes were first included in the standard's first edition in 1974. ISO does not invent country names: those come from United Nations sources, specifically the UN Terminology Bulletin Country Names and the Country and Region Codes for Statistical Use. When the UN notifies ISO of a new member state, the ISO 3166 Maintenance Agency assigns it a code.

There are 249 currently assigned alpha-2 codes. That number is larger than the count of sovereign countries because the standard also covers dependent territories and special areas of geographic interest. Antarctica has a code (AQ). So does the Vatican (VA), Åland (AX), and Bouvet Island (BV), which is uninhabited.

ISO 3166-1 defines three code formats for each entry:

ISO recommends alpha-2 as the general-purpose code, which is why it is the one you meet most often.

02The Exceptions That Break Integrations

This is the section worth reading before the table. Every one of these has caused a production bug somewhere.

The European Commission does not use GR or GB. It uses EL for Greece and UK for the United Kingdom. Neither is a valid ISO 3166-1 alpha-2 code. If you are parsing EU documents, VAT numbers, or Eurostat data, you will meet both, and a strict ISO validator will reject them.

GB is the code, .uk is the domain. The ISO code for the United Kingdom is GB. The country code top-level domain is .uk. UK is reserved in ISO 3166-1 at the request of the UK government, but it is not the assigned code. Both exist and they are not the same thing.

Kosovo has no ISO code. It is not a UN member state, so the ISO 3166 Maintenance Agency has not assigned it one. In practice many systems use XK, which is a user-assigned code adopted by the European Commission, the IMF, and SWIFT. It will fail any validator checking against the official list. If you accept addresses from the Balkans, decide deliberately how to handle this.

Some ccTLDs are not their country's code. .eu is not a country. .io belongs to the British Indian Ocean Territory. .tv is Tuvalu. .ai is Anguilla. .me is Montenegro. Treating a domain suffix as a country code will misroute traffic.

You can safely invent codes, in a defined range. ISO reserves AA, QM to QZ, XA to XZ, and ZZ as user-assigned. The Maintenance Agency will never assign these, so they are safe for internal entities that need a slot. That is where XK for Kosovo comes from.

Codes get retired, and reused. ISO 3166-3 exists to track former countries. Czechoslovakia is CSHH, Yugoslavia is YUCS, East Germany is DDDE. More dangerously, retired alpha-2 codes can be reassigned after a waiting period. If you store a country code as your primary key rather than as a display value, this eventually breaks.

Currency codes are built from them. The first two characters of an ISO 4217 currency code are the country's alpha-2 code. USD, GBP, JPY, CHF. Currencies that belong to no single country start with X: XAU for gold, XDR for IMF special drawing rights.

Case is technically insensitive. ISO 3166-1 alpha-2 codes should be treated as case-insensitive, though convention is uppercase. Locale identifiers follow a different convention: lowercase language, uppercase region, as in en-US or pt-BR.

Taiwan's entry is politically formatted. The ISO short name is "Taiwan, Province of China." If you render ISO names directly in a user-facing dropdown, you will get complaints. Most teams maintain a display-name override layer.

03Where Two-Letter Country Codes Are Used

• Country code top-level domains. .de, .fr, .jp, with the exceptions noted above.
• Locale and language tags. BCP 47 combines a language subtag with a region subtag: en-GB, fr-CA, zh-CN.
• HTML. The lang attribute, as in <html lang="en-US">.
• ISO 4217 currency codes, where the first two letters are the country.
• ISO 3166-2 subdivision codes, which prefix the country code: ID-RI is Riau in Indonesia, NG-RI is Rivers in Nigeria.
• International shipping and postal exchange, where containers are labelled by country code.
• Machine-readable passports, which use alpha-3.
• IBAN, where the first two characters are the country's alpha-2 code.
• Phone number metadata, where libraries key on alpha-2 rather than dialling code, since dialling codes are shared.

04The Complete List: All 249 ISO 3166-1 Alpha-2 Codes

Sorted alphabetically by official ISO short name in English. Current as of 26 August 2026.

05Former Country Codes (ISO 3166-3)

When a country ceases to exist, changes its name, or splits, its entry moves to ISO 3166-3 and receives a four-letter code. The first two letters are usually the old alpha-2 code. There are 31 such entries.

06Working With Country Codes in Code

Three rules that prevent most country code bugs.

1. Store the code, display the name separately. Country names change (Turkey to Türkiye, Swaziland to Eswatini, Macedonia to North Macedonia). Codes are more stable, but not permanent. Keep an internal identifier as your key, the ISO code as an attribute, and the display name in a layer you control.

2. Validate against a current list, not a hardcoded one. A country list copied into a constants file in 2019 is wrong. South Sudan (SS) was assigned in 2011, Curaçao (CW) and Sint Maarten (SX) in 2010, Bonaire, Sint Eustatius and Saba (BQ) the same year.

3. Decide your policy on non-ISO codes before you meet them. EL, UK, and XK will arrive in real data. Silently rejecting them produces support tickets. Silently accepting them corrupts your data. Map them explicitly.

07Getting Country Codes Programmatically

If you would rather not maintain a country list, two endpoints in the ApyHub catalog cover it.

The Countries Dictionary API returns a mapping of alpha-2 codes to country names:

json

The Country Information API returns fuller detail for a single country: flags, calling codes, currencies, and administrative subdivisions.

Both run on the free plan, which requires no credit card and allows 5 calls a day. For a country list you fetch once and cache, that is genuinely enough. Related endpoints include the Language Dictionary API and the Phone Number Formatter API, which keys on alpha-2 rather than dialling code for the reason described above.

Browse standard data APIs →

08Comparing Country Data APIs

For a static list that rarely changes, a bundled dataset is genuinely fine and cheaper than an API call. An API earns its place when you need the surrounding metadata, when you want the update problem to be someone else's, or when the same key already covers other things you call.

09Sources

• ISO 3166 Country Codes, the standard's official page
• ISO 3166-1 alpha-2 on Wikipedia, which tracks assignment years and reserved codes
• DataHub country list, maintained against ISO 3166/MA changes

10FAQ

How many two-letter country codes are there? There are 249 currently assigned ISO 3166-1 alpha-2 codes. That exceeds the number of sovereign states because the standard also covers dependent territories and special areas of geographic interest, including Antarctica (AQ) and uninhabited islands like Bouvet Island (BV).

What is a two-letter country code? A two-letter country code, formally an ISO 3166-1 alpha-2 code, is a two-character identifier assigned by the ISO 3166 Maintenance Agency to represent a country, dependent territory, or special area. US is the United States, DE is Germany, JP is Japan.

What is the difference between alpha-2, alpha-3, and numeric country codes? Alpha-2 uses two letters (US) and is ISO's recommended general-purpose code. Alpha-3 uses three letters (USA) and more closely resembles the country name. Numeric-3 uses three digits (840) and is script-independent, which matters for systems not using the Latin alphabet.

Why does the EU use EL for Greece and UK for the United Kingdom? Both are European Commission conventions that predate or diverge from ISO. The ISO codes are GR and GB. Neither EL nor UK is valid ISO 3166-1 alpha-2, so a strict validator will reject them even though they appear throughout EU documents and VAT numbers.

What is the country code for Kosovo? Kosovo has no official ISO 3166-1 code, because it is not a UN member state. XK is widely used in practice and has been adopted by the European Commission, the IMF, and SWIFT, but it is a user-assigned code and will fail validation against the official list.

Is the UK's country code UK or GB? GB is the ISO 3166-1 alpha-2 code. UK is reserved at the request of the UK government and is used as the country code top-level domain, but it is not the assigned ISO code.

Can I make up my own country codes? Yes, within a defined range. ISO reserves AA, QM to QZ, XA to XZ, and ZZ for user assignment and will never allocate them officially. XK for Kosovo is the best-known example of this in practice.

Are two-letter country codes case-sensitive? No. ISO 3166-1 alpha-2 codes should be treated as case-insensitive, though they are conventionally written in uppercase. Locale identifiers use a mixed convention: lowercase language, uppercase region, as in en-US.

What happens when a country changes its name or ceases to exist? Its entry moves to ISO 3166-3 and receives a four-letter code, usually built from the old alpha-2 code. Czechoslovakia is CSHH and Yugoslavia is YUCS. Retired alpha-2 codes can be reassigned later, which is why storing a country code as a database primary key is risky.

Are ccTLDs the same as country codes? Usually, but not always. Most ccTLDs derive from alpha-2 codes, but .uk differs from GB, .eu is not a country at all, and several small territories license their domains commercially, which is why .io, .tv, and .ai appear on sites with no connection to those places.

Where do currency codes come from? The first two characters of an ISO 4217 currency code are the country's alpha-2 code: USD, GBP, JPY. Currencies not tied to one country begin with X, such as XAU for gold and XDR for IMF special drawing rights.

How do I get country codes programmatically? Either bundle a maintained dataset in your application, or call an API. ApyHub's Countries Dictionary API returns alpha-2 codes mapped to names, and the Country Information API returns fuller detail per country. Both are available on a free plan with no credit card.

Should I use an API or a static list? For a list that changes roughly once a year, a bundled dataset is fine and faster. An API is worth it when you need the surrounding metadata like flags, calling codes, and subdivisions, when you would rather not own the update problem, or when the same credential already covers other services you call.

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