63123 ZIP Code, Saint Louis, MO

63123 is a ZIP code in Saint Louis, Missouri in St. Louis County. It covers 12 square miles of land. The closest ZIP codes are 63125, 63126 and 63109. 49,077 people live here in 21,755 households, which puts it among the most populous 1% of Missouri ZIP codes. At about 3,941 people per square mile it has suburban density, and most homes are owner-occupied (75%). Median household income is $77,055, close to the Missouri median of $70,702.

Quick facts

Key figures

MeasureValue
Residents49,077
Households21,755
Median household income$77,055
Income per person$44,373
Median age40.9
Homeowners74.9%
Median home value$219,400
Median rent$1,006
Bachelor's degree or higher37.6%
Average commute (minutes)23.7
Households with kids under 1823.3%
Moved in the past year10.3%
Below the poverty line7.9%
Broadband internet93.3%
Speak a non-English language at home16.1%

Household income

% of householdsValue
<$10K3.5%
$10–15K2.2%
$15–25K4.5%
$25–35K7.7%
$35–50K12.5%
$50–75K18.0%
$75–100K15.7%
$100–150K19.4%
$150–200K8.2%
$200K+8.3%

Age

% of all residentsValue
<109.5%
10–1910.6%
20–246.2%
25–3413.7%
35–4415.7%
45–5410.7%
55–6414.4%
65–7411.3%
75+8.1%

Tenure

% of housing unitsValue
Owned, with mortgage44.9%
Owned outright25.9%
Rented23.1%
Vacant6.0%

Type of building

% of housing unitsValue
Detached house77.2%
Townhome1.6%
2–4 units7.6%
5–19 units9.5%
20+ units3.7%
Mobile / other0.3%

Businesses in 63123

915 business establishments with 13,475 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

63123 has 45 USPS carrier routes with 22,718 residential and 933 business mailboxes. Open the EDDM route map.

Carrier routes in 63123

63123 has 45 USPS carrier routes (45 city (C)) with 22,718 residential and 933 business mailboxes. Routes range from 109 homes (C046) to 786 homes (C037); the median route has 493 homes. The Census counted 21,755 households in 63123 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2491
250–49923
500–74919
750–9992
1,000–1,4990
1,500+0

Best routes in 63123 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route C046 — USPS business mailboxes 269, 109 homes
  2. Route C048 — USPS business mailboxes 85, 334 homes
  3. Route C034 — USPS business mailboxes 80, 422 homes
  4. Route C073 — USPS business mailboxes 76, 429 homes
  5. Route C041 — USPS business mailboxes 62, 416 homes

Select these 5 routes on the route map

Every carrier route in 63123

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C002City7592$101,964———
C005City40260$81,858———
C009City4461$57,929———
C021City3185$90,655———
C023City3983$53,487———
C024City4246$81,858———
C025City5811$74,384———
C026City53411$70,394———
C029City3771$101,964———
C030City6591$100,727———
C031City7365$35,417———
C034City42280$101,520———
C035City52739$35,417———
C036City49311$101,520———
C037City7868$58,180———
C038City64913$125,006———
C039City4086$80,781———
C040City5550$125,006———
C041City41662$76,763———
C042City42327$70,451———
C043City59111$77,310———
C044City5490$80,781———
C045City4912$78,694———
C046City109269$76,763———
C047City3952$55,651———
C048City33485$76,763———
C049City56716$56,924———
C050City5543$51,251———
C051City58717$53,487———
C052City4780$125,006———
C053City46741$81,858———
C056City59119$70,394———
C057City7176$76,494———
C058City3448$81,283———
C059City4930$125,006———
C060City5272$100,727———
C063City6599$56,924———
C064City4660$71,067———
C066City5210$78,157———
C067City6033$53,487———
C069City5822$63,390———
C072City4430$80,781———
C073City42976$84,932———
C074City48311$84,932———
C075City4259$58,180———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 63123 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

Areas that include 63123

Where it ranks

Mail every home in 63123

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 63123, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 63123 in?
63123 is a Saint Louis, MO mailing address. By land area, 37% lies inside Affton, 11% lies inside Green Park, 10% lies inside Concord and 7% lies inside Grantwood Village; the rest is outside any Census-defined city or community.
What county is 63123 in?
63123 is in St. Louis County.
What is the population of 63123?
About 49,077 people (±1,858), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 50,989.
What is the median household income in 63123?
$77,055 (±$3,496), compared with $70,702 for Missouri as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 63123?
45 USPS carrier routes with 22,718 residential and 933 business mailboxes (23,665 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 63123?
The closest, measured center to center: 63125 (2.7 mi, Lemay), 63126 (2.7 mi, Crestwood), 63109 (3.1 mi, St. Louis), 63119 (3.2 mi, Webster Groves), 63116 (4.1 mi, St. Louis) and 63111 (4.3 mi, St. Louis).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.