Last reviewed: September 2, 2026
Country codes provide short, standardized identifiers for countries and territories. Two formats you will see constantly are the two-letter alpha-2 code and three-letter alpha-3 code. They are used in databases, forms, logistics, statistics, internet systems and many international datasets.
Alpha-2 vs. alpha-3
Alpha-2 codes use two letters and are compact enough for interfaces and machine-readable fields. Alpha-3 codes use three letters and are often easier for people to recognize. For example, the United States appears as US in alpha-2 form and USA in alpha-3 form.
Country-code lookup
What country codes should not be used for
A code is an identifier, not a statement about nationality, citizenship, political status or the exact geographic extent of a place. When a legal, customs or compliance workflow depends on an official list, use the authority responsible for that workflow.