Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/CA/MOST-TAX-RETURNS

ZIP Codes With the Most Tax Returns Filed in California

What this measures. Number of individual income tax returns filed. A rough proxy for how many households a ZIP code contains, available where census figures are not. Source: IRS Statistics of Income, ZIP code data, data release 2026-10-12.

# ZIP City County Returns filed
1 92336 Fontana San Bernardino 49,980
2 90650 Norwalk Los Angeles 47,880
3 92154 San Diego San Diego 47,170
4 94565 Pittsburg Contra Costa 44,700
5 92683 Westminster Orange 44,410
6 91331 Pacoima Los Angeles 44,100
7 91342 Sylmar Los Angeles 43,820
8 91911 Chula Vista San Diego 43,810
9 90250 Hawthorne Los Angeles 43,650
10 92335 Fontana San Bernardino 42,830
11 92503 Riverside Riverside 41,220
12 90280 South Gate Los Angeles 41,020
13 90805 Long Beach Los Angeles 40,860
14 94112 San Francisco San Francisco 40,260
15 90011 Los Angeles Los Angeles 40,200
16 95747 Roseville Placer 40,160
17 91910 Chula Vista San Diego 40,060
18 90201 Bell Gardens Los Angeles 39,940
19 92704 Santa Ana Orange 39,020
20 92804 Anaheim Orange 38,870
21 92376 Rialto San Bernardino 38,820
22 95035 Milpitas Santa Clara 38,430
23 91744 La Puente Los Angeles 38,290
24 92126 San Diego San Diego 37,900
25 91710 Chino San Bernardino 37,500
26 90044 Los Angeles Los Angeles 37,490
27 93722 Fresno Fresno 37,330
28 91709 Chino Hills San Bernardino 37,230
29 95630 Folsom Sacramento 36,900
30 94544 Hayward Alameda 36,480
31 95076 Watsonville Santa Cruz 36,480
32 92345 Hesperia San Bernardino 36,170
33 93065 Simi Valley Ventura 36,160
34 92509 Riverside Riverside 35,740
35 90706 Bellflower Los Angeles 35,440
36 93033 Oxnard Ventura 35,440
37 93727 Fresno Fresno 35,370
38 94533 Fairfield Solano 35,340
39 91335 Reseda Los Angeles 35,060
40 92805 Anaheim Orange 34,950
41 92592 Temecula Riverside 34,840
42 91706 Baldwin Park Los Angeles 34,770
43 94110 San Francisco San Francisco 34,310
44 93307 Bakersfield Kern 33,980
45 94587 Union City Alameda 33,580
46 95823 Sacramento Sacramento 33,440
47 92630 Lake Forest Orange 33,200
48 94080 South San Francisco San Mateo 33,190
49 90631 La Habra Orange 32,770
50 92553 Moreno Valley Riverside 32,740

Showing the top 50 of 1,475 ZIP codes in California that have this figure . 92336 ranks 1st at 49,980, against 32,740 in 50th place.

Other rankings for California

Cite this page

zipcodes.pro. “ZIP Codes With the Most Tax Returns Filed in California.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/ca/most-tax-returns

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