AZ is Arizona. The capital and largest city is Phoenix, and Arizona joined the Union on February 14, 1912, as the 48th state.
Why the code is AZ
Four state names begin with A, and only two of them could keep their first two letters. When the Post Office Department published its two-letter list in October 1963, the point was to squeeze the city, the state and the brand new ZIP code onto a single address line. Alabama took AL. Arkansas took AR. Arizona spells its own first two letters A and R as well, so it lost that pair to Arkansas and had to reach further into the name.
It reached to the fourth position. A-r-i-z-o-n-a gives the z, and Arizona is the only state name that contains one. That makes AZ the only code in the set of fifty with a z in it, so a smudged or half-printed label still cannot be read as any other state. Alaska was displaced by Alabama in exactly the same way and ended up with AK. The 48th and 49th states, admitted 47 years apart, both wound up with the leftover consonants.
Before 1963, printers and clerks wrote Ariz. That form never disappeared. Legal citation still uses Ariz., and newspaper style guides keep it for datelines. AZ was invented for sorting machines, not for sentences, which is why "he moved to AZ" reads oddly in a paragraph but looks perfectly normal above a ZIP code.
Codes people confuse with AZ
| Code | Stands for | Why the mix-up happens |
|---|---|---|
| AR | Arkansas | Arizona's own first two letters are A and R. Arkansas got there first, so the code that looks correct is the wrong one. |
| AK | Alaska | Both states were bumped off the obvious pair and given a hard consonant instead, so the two look like a matched set. |
| AL | Alabama | Dropdown menus on web forms run AL, AK, AZ, AR. Four A entries in a row, one click apart. |
| ARI | Arizona in sports | The Cardinals and the Diamondbacks are both ARI in box scores. Broadcast abbreviations use three letters and ignore the postal list entirely. |
| AZ | Azerbaijan | ISO 3166 assigns AZ to Azerbaijan, so customs forms and .az domains reuse the same two letters for a country nine time zones away. |
Quick facts about Arizona
- Capital: Phoenix
- Largest city: Phoenix, which is the capital as well
- Region: West, in the Southwest group with New Mexico, Nevada and Utah
- Statehood: February 14, 1912, the 48th state and the last of the contiguous 48
- Population band: 5 to 10 million
- Size: 6th largest state by area
- Time: Mountain time, and most of the state does not change its clocks for daylight saving
Where you will see AZ
On mail. The code sits on the last line, between the city and the ZIP code. Arizona ZIP codes begin with 85 or 86, so an envelope reading Phoenix AZ 85004 carries the state name twice over, once in letters and once in digits.
On the road. Arizona plates spell the state name out in full, so the two-letter code lives on the registration card, the insurance document and the vehicle title rather than on the metal itself.
In sports. Almost never. Professional leagues write ARI, colleges write ASU or UA, and the Phoenix Suns skip the state entirely. AZ on a scoreboard usually means someone typed the postal code by mistake.
In crosswords. Clues like "Grand Canyon st." or "Phoenix's state, briefly" want AZ. The z is a useful letter for a constructor, which is why the code appears in grids more often than its population would suggest.
Can you place AZ without thinking?
Statedoku uses postal codes as puzzle constraints. Solve one grid a day and the four A states stop blurring together.
Play today's puzzle →