ISO 国家代码（二字 / 三字）
二字码常见于域名与语言标签（如 en-US）；三字码多见金融与贸易单据。
| 国家 / 地区 | 二字码 | 三字码 |
|---|---|---|
| United States | US | USA |
| Canada | CA | CAN |
| United Kingdom | GB | GBR |
| Ireland | IE | IRL |
| France | FR | FRA |
| Germany | DE | DEU |
| Spain | ES | ESP |
| Italy | IT | ITA |
| Netherlands | NL | NLD |
| Belgium | BE | BEL |
| Switzerland | CH | CHE |
| Sweden | SE | SWE |
| Norway | NO | NOR |
| Denmark | DK | DNK |
| Poland | PL | POL |
| Portugal | PT | PRT |
| Russia | RU | RUS |
| Turkey | TR | TUR |
| United Arab Emirates | AE | ARE |
| Saudi Arabia | SA | SAU |
| India | IN | IND |
| China | CN | CHN |
| Hong Kong | HK | HKG |
| Taiwan | TW | TWN |
| Japan | JP | JPN |
| South Korea | KR | KOR |
| Singapore | SG | SGP |
| Thailand | TH | THA |
| Vietnam | VN | VNM |
| Indonesia | ID | IDN |
| Malaysia | MY | MYS |
| Philippines | PH | PHL |
| Australia | AU | AUS |
| New Zealand | NZ | NZL |
| Brazil | BR | BRA |
| Mexico | MX | MEX |
| Argentina | AR | ARG |
| South Africa | ZA | ZAF |
| Egypt | EG | EGY |
| Nigeria | NG | NGA |
说明
- 英国在 ISO 3166-1 中为 GB；UK 是另列的保留码。
- 本表为高频子集，不是完整 ISO 清单。