County ZIP codes · Ohio · FIPS 39003

Allen County, OH ZIP Codes

Allen County, Ohio has 20 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 19 residential and 1 for PO boxes or a single organization. 13 of the residential ones lie mainly in Allen County and 6 mainly in a neighboring county; 11 cross the county line. Median household income ranges from $44,045 in 45812 (Alger) to $88,792 in 45844 (Fort Jennings) (Census Bureau, ACS 2020-2024).

ACS2020-24
Census2020

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

45812 · $44k 45844 · $89k

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $62,449 and $76,848.

They carry 15 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 19 residential ZIP codes in Allen County

13 ZIP codes lie mainly in Allen County; 6 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Allen County, largest first; "In this county" is the share of the ZIP's land in the county
						In this county
45805	Lima	24,387	1,673	$69k	$161k	100%
45801	Lima	21,739	476	$52k	$124k	100%
45804	Lima	13,608	640	$45k	$100k	100%
45807	Lima	11,774	156	$71k	$204k	100%
45806	Lima	10,974	176	$83k	$212k	78%
45833	Delphos	10,919	151	$65k	$161k	46%
45817	Bluffton	5,926	93	$77k	$210k	50%
45887	Spencerville	4,422	63	$68k	$184k	55%
45850	Harrod	3,559	61	$85k	$194k	81%
45820	Cairo	581	2,097	$83k	$115k	100%
45808	Beaverdam	350	586	$82k	$101k	100%
45854	Lafayette	293	763	$53k	$121k	100%
45809	Gomer	45	142	–	$154k	100%

Partly in Allen County

Residential ZIP codes mainly in another county that reach at least 1% into Allen County, by their share here
						In this county
45830	Columbus Grove	5,199	55	$81k	$170k	33%
45877	Pandora	2,562	96	$69k	$179k	9%
45810	Ada	7,449	114	$64k	$168k	8%
45896	Waynesfield	1,833	50	$62k	$173k	6%
45844	Fort Jennings	3,059	53	$89k	$231k	5%
45812	Alger	2,027	52	$44k	$137k	2%

Download the 20 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

11 ZIP codes of Allen County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Allen County and in the neighboring counties
ZIP	In Allen	Elsewhere
45806	78%	Auglaize County 22%
45833	46%	Van Wert County 45%; Putnam County 9%
45810	8%	Hardin County 80%; Hancock County 12%
45817	50%	Hancock County 47%; Putnam County 3%
45830	33%	Putnam County 67%
45887	55%	Auglaize County 24%; Van Wert County 18%; Mercer County 3%
45850	81%	Hardin County 15%; Auglaize County 4%
45844	5%	Putnam County 87%; Van Wert County 8%
45877	9%	Putnam County 90%
45812	2%	Hardin County 98%
45896	6%	Auglaize County 81%; Hardin County 13%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

PO Box and single-organization ZIP codes

ZIP codes in Allen County without a residential area (GeoNames postal codes)
ZIP	Postal name
45802	Lima

Source: GeoNames postal codes (CC BY 4.0).

Which first three digits do Allen County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Allen County starts with 458.

Three-digit prefixes of Allen County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Allen County's
Prefix	Sectional center	Here	All codes
458	Columbus, OH (SCF 430)	20	85

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.

Where are the ZIP codes of Allen County?