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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 — ZIP/06423

06423

ZIP 06423 is East Haddam, Connecticut, in Middlesex County; area codes 860 and 959; Eastern time.

Type
Standard
Time zone
America/New_York
County
Middlesex
Metro area
none
Population
5,182
Coordinates
41.4566, -72.3914
☼ Live from 06423 — East Haddam, CT

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Where 06423 is

Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.

★ Weird and wonderful facts about 06423
  • 🔢 Type 06423 into a pocket calculator and turn it upside down: EZhgO — not quite a word, sorry.
  • ➕ As a number, 6,423 = 3 × 2141. Its digits add up to 15, a total 1,657 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1100100010111
  • 🏠 Its numerical neighbours: 06422 (Durham, CT, 15 mi away) and 06424 (East Hampton, CT, 9 mi away).
  • 🔄 Backwards, 06423 becomes 32460 — and that is a real ZIP code: Sneads, FL, 1,016 miles away.
  • 👥 63 other ZIP codes are made of exactly the same digits (02346, 02364, 02634, 02643, 03246, 03264, …). The farthest-flung twin is 34260 in Manasota, FL, 1,124 miles away.
  • 🧭 Farther north than 70% of all ZIP codes, and farther east than 94%.
  • 🎯1,372 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 06423 and you would come out at 41.46°S, 107.61°E — 799 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 11m of daylight. Shortest: 9h 10m.
  • 📏 At 36.6 square miles of land, 06423 is bigger than 51% of ZIP codes — room for about 28 Central Parks.
🌙 The sky over 06423 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population5,182This ZIP5,182
Households2,137This ZIP2,137
Housing units2,441This ZIP2,441
Median age51.7This ZIP51.7Connecticut41.1US 38.9
Median household income$107,549This ZIP$107,549Connecticut$95,781US $80,734
Median home value$373,700This ZIP$373,700Connecticut$366,900US $332,700
Median gross rent$1,663This ZIP$1,663Connecticut$1,488US $1,413
Bachelor's degree or higher39.4%This ZIP39.4%
Mean commute32.6 minThis ZIP32.6 min
Population density141.7 / sq miThis ZIP141.7 / sq mi

Business and tax activity

Business establishments80This ZIP80
Employees525This ZIP525
Annual payroll$32,378,000This ZIP$32,378,000
Tax returns filed2,610This ZIP2,610
Total adjusted gross income$307,612,000This ZIP$307,612,000

Land area

Land area36.57 sq miThis ZIP36.57 sq mi
Water area1.71 sq miThis ZIP1.71 sq mi

Other place names in 06423

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 06423

ZIPCityDistance
06439 Hadlyme, CT 2.9 mi
06469 Moodus, CT 4.6 mi
06412 Chester, CT 5.9 mi
06438 Haddam, CT 6.2 mi
06415 Colchester, CT 6.8 mi
06420 Salem, CT 7.2 mi
06426 Essex, CT 7.3 mi
06371 Old Lyme, CT 7.4 mi
06417 Deep River, CT 7.6 mi
06409 Centerbrook, CT 7.7 mi

Find every ZIP code within 10 miles of 06423 →

Questions about this ZIP code

Where is ZIP code 06423?

06423 is in East Haddam, Connecticut, in Middlesex County. Its published point location is 41.4566, -72.3914.

What county is 06423 in?

06423 lies in Middlesex County.

What area code is 06423?

East Haddam uses area codes 860 and 959, from NANPA's telephone records.

What time zone is 06423 in?

06423 uses America/New_York.

How many people live in 06423?

About 5,182 people live in ZIP code 06423, in 2,137 households, at 141.7 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.

What is the median household income in 06423?

$107,549 a year, against $95,781 across Connecticut.

What ZIP codes are near 06423?

The closest are 06439 (2.9 mi), 06469 (4.6 mi), 06412 (5.9 mi), 06438 (6.2 mi) and 06415 (6.8 mi).

Is 06423 a PO Box ZIP code?

06423 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “06423 ZIP Code — East Haddam, Connecticut (Middlesex County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/06423

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