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/ME/MOST-TAX-RETURNS

ZIP Codes With the Most Tax Returns Filed in Maine

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 04401 Bangor Penobscot 21,510
2 04103 Portland Cumberland 16,460
3 04240 Lewiston Androscoggin 16,350
4 04106 South Portland Cumberland 14,980
5 04330 Augusta Kennebec 13,170
6 04005 Biddeford York 12,560
7 04074 Scarborough Cumberland 12,000
8 04901 Waterville Kennebec 11,920
9 04072 Saco York 11,500
10 04210 Auburn Androscoggin 11,440
11 04011 Brunswick Cumberland 11,100
12 04092 Westbrook Cumberland 10,730
13 04062 Windham Cumberland 10,250
14 04101 Portland Cumberland 10,120
15 04102 Portland Cumberland 9,430
16 04038 Gorham Cumberland 9,080
17 04073 Sanford York 8,970
18 04605 Ellsworth Hancock 7,260
19 04105 Falmouth Cumberland 6,600
20 04090 Wells York 6,540
21 04043 Kennebunk York 6,530
22 04345 Gardiner Kennebec 6,300
23 04530 Bath Sagadahoc 6,080
24 03909 York York 5,610
25 04064 Old Orchard Beach York 5,400
26 04086 Topsham Sagadahoc 5,290
27 04412 Brewer Penobscot 4,950
28 04107 Cape Elizabeth Cumberland 4,870
29 04444 Hampden Penobscot 4,850
30 04096 Yarmouth Cumberland 4,680
31 04915 Belfast Waldo 4,610
32 04976 Skowhegan Somerset 4,570
33 04039 Gray Cumberland 4,510
34 03904 Kittery York 4,490
35 04032 Freeport Cumberland 4,470
36 04046 Kennebunkport York 4,430
37 04093 Buxton York 4,410
38 04468 Old Town Penobscot 4,360
39 04084 Standish Cumberland 4,300
40 04769 Presque Isle Aroostook 4,300
41 04730 Houlton Aroostook 4,180
42 04002 Alfred York 4,170
43 04736 Caribou Aroostook 4,150
44 03901 Berwick York 4,080
45 03908 South Berwick York 3,930
46 04938 Farmington Franklin 3,910
47 04963 Oakland Kennebec 3,730
48 04841 Rockland Knox 3,710
49 03903 Eliot York 3,680
50 04280 Sabattus Androscoggin 3,540

Showing the top 50 of 370 ZIP codes in Maine that have this figure . 04401 ranks 1st at 21,510, against 3,540 in 50th place.

Other rankings for Maine

Cite this page

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

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