US State Abbreviations: Full List of 50 States + DC (Two-Letter Codes)

Every US state has an official two-letter abbreviation defined by the United States Postal Service (USPS): Texas is TX, California is CA, New York is NY, Washington State is WA. The codes are always two uppercase letters, and they are what address forms, payment processors and shipping APIs expect in the State field.

Washington, DC (District of Columbia) is not a state, but nearly every address form treats it as one and uses the code DC. If your form's state dropdown has 50 entries instead of 51, DC is usually the one missing — and DC residents will not be able to check out.

WA is Washington State on the Pacific coast; DC is Washington, the capital city. They are different places with different ZIP ranges (WA: 98xxx–99xxx, DC: 20xxx), so mixing them up fails ZIP-state consistency checks.

New York needs care in two fields: State is NY, and only City takes the value New York. Other frequent confusions: MI is Michigan (not Mississippi, which is MS; Missouri is MO), AL is Alabama (Alaska is AK), and AR is Arkansas (Arizona is AZ).

Most checkout forms show the full state name in a dropdown but submit the two-letter code in the payload. When you test a form, assert on the submitted value, not the visible label — seeing California on screen does not guarantee the API received CA.

Payment (AVS), tax and shipping services generally require the two-letter code plus a ZIP code that actually belongs to that state. If you need format-correct sample data where the state, city and ZIP all match, generate it with the state pages linked in the table above, or call the free API.