ISO 3166-2 Subdivision Lookup
ISO 3166-2 codes for US states and Canadian provinces.
Overview
The ISO 3166-2 Subdivision Lookup returns the standard subdivision code for any US state or Canadian province. Type "California" and you get US-CA; type "Quebec" and you get CA-QC. The reverse direction also works: paste in a code and the tool returns the full subdivision name and the parent country.
Subdivision codes show up in shipping APIs, billing systems, geographic dropdowns, customs forms, and almost every system that needs a stable identifier for a state or province. ISO 3166-2 is the global standard - the same scheme that identifies UK countries (GB-ENG, GB-SCT), Mexican states (MX-CMX) and Japanese prefectures (JP-13). This tool focuses on the two highest-volume cases for English-speaking users: the 50 US states plus DC and territories, and the 13 Canadian provinces and territories.
How it works
ISO 3166-2 builds subdivision codes by prefixing the country's alpha-2 code with a hyphen and a 1-3 character subdivision identifier. The full code uniquely identifies a state or province globally - US-CA is unambiguous in a way that a bare "CA" is not (it could be California or Canada). The tool stores the canonical list of subdivision codes and their preferred English names; lookup is case-insensitive and accepts either the bare two-letter postal abbreviation (CA, QC) or the full code (US-CA, CA-QC).
For Canada, the codes line up neatly with the Canada Post two-letter abbreviations. For the US, the codes match USPS state abbreviations exactly, including DC, the territories (US-PR, US-GU, US-VI, US-AS, US-MP) and the outlying minor islands.
Examples
- California →
US-CA- the standard code for California. - Quebec →
CA-QC- Canadian province of Quebec. US-DC→ District of Columbia, United States.CA-NU→ Nunavut, Canada.
FAQ
How is this different from a postal abbreviation?
US postal abbreviations and Canadian provincial abbreviations are the bare two-letter forms. ISO 3166-2 prefixes them with the country code and a hyphen, removing all ambiguity for international systems.
Does the tool cover all countries?
This page is limited to US and Canadian subdivisions, the highest-volume case. The full ISO 3166-2 standard covers every country, but those are not included here.
Are US territories listed as states?
Territories such as Puerto Rico (US-PR) and Guam (US-GU) get their own ISO 3166-2 codes. They are listed separately from the 50 states but use the same US- prefix.
What about combined country/region codes for shipping?
Most carriers accept either US-CA or just CA when paired with a US country field. The full ISO 3166-2 form is preferred whenever the country is not already disambiguated by a separate field.