ZIP codes and county lines in Pennsylvania

361 of the 1833 ZIP code areas in Pennsylvania, or 19.7%, overlap more than one county. If your territories, tax rules or service areas are set by county and your list is by ZIP, these are the rows where the two disagree.

ZIP code areas: 1,833
In more than one county: 361
At least 5% in a second county: 273
Cross a state line: 0

How Pennsylvania compares

Pennsylvania ranks 32 of 52 (the 50 states, DC and Puerto Rico) by the share of its ZIP code areas that overlap more than one county. 67 of its counties have at least one split ZIP code area along an edge.

Counties with the most split ZIP code areas

Allegheny County: 27 ZIP codes shared with another county
Montgomery County: 26 ZIP codes shared with another county
Westmoreland County: 25 ZIP codes shared with another county
Berks County: 24 ZIP codes shared with another county
Luzerne County: 19 ZIP codes shared with another county

Every split ZIP code area in Pennsylvania

Each row is one ZCTA and the counties its land falls in, largest share first. Counties in another state are marked with that state. Sort by the share outside the main county to put the most evenly divided ones first.

	Share of land by county
15003	Beaver County 94.9% Allegheny County 5.1%	5.1%	2
15005	Beaver County 73.3% Allegheny County 26.7%	26.7%	2
15012	Westmoreland County 84.8% Fayette County 14.9% Washington County 0.3%	15.2%	3
15017	Allegheny County 86.7% Washington County 13.3%	13.3%	2
15021	Washington County 99.5% Beaver County 0.5%	0.5%	2
15026	Beaver County 71.9% Allegheny County 23.5% Washington County 4.7%	28.1%	3
15044	Allegheny County 96.8% Butler County 3.2%	3.2%	2
15057	Washington County 65.4% Allegheny County 34.6%	34.6%	2
15063	Washington County 60.6% Allegheny County 39.4%	39.4%	2
15068	Westmoreland County 78.0% Allegheny County 22.0%	22.0%	2
15083	Westmoreland County 87.5% Allegheny County 12.5%	12.5%	2
15085	Westmoreland County 97.6% Allegheny County 2.4%	2.4%	2
15086	Allegheny County 75.2% Butler County 24.8%	24.8%	2
15089	Westmoreland County 98.5% Allegheny County 1.5%	1.5%	2
15102	Allegheny County 99.2% Washington County 0.8%	0.8%	2
15126	Allegheny County 99.1% Washington County 0.9%	0.9%	2
15129	Allegheny County 98.0% Washington County 2.0%	2.0%	2
15131	Allegheny County 94.8% Westmoreland County 5.3%	5.3%	2
15137	Allegheny County 100.0% Westmoreland County under 0.1%	under 0.1%	2
15143	Allegheny County 90.1% Beaver County 9.9%	9.9%	2
15146	Allegheny County 99.7% Westmoreland County 0.3%	0.3%	2
15241	Allegheny County 99.0% Washington County 1.0%	1.0%	2
15321	Washington County 85.9% Allegheny County 14.1%	14.1%	2
15322	Greene County 80.5% Washington County 19.4%	19.4%	2
15329	Washington County 71.9% Greene County 28.1%	28.1%	2
15332	Washington County 86.9% Allegheny County 13.1%	13.1%	2
15345	Washington County 96.4% Greene County 3.6%	3.6%	2
15370	Greene County 100.0% Washington County under 0.1%	under 0.1%	2
15377	Washington County 69.3% Greene County 30.7%	30.7%	2
15417	Washington County 50.5% Fayette County 49.5%	49.5%	2
15424	Somerset County 75.2% Fayette County 24.8%	24.8%	2
15501	Somerset County 95.4% Westmoreland County 4.6%	4.6%	2
15531	Somerset County 87.4% Westmoreland County 12.6%	12.6%	2
15533	Bedford County 94.0% Fulton County 6.0%	6.0%	2
15534	Bedford County 99.1% Somerset County 0.9%	0.9%	2
15545	Bedford County 58.2% Somerset County 41.8%	41.8%	2
15557	Somerset County 99.2% Fayette County 0.8%	0.8%	2
15559	Bedford County 99.9% Somerset County 0.1%	0.1%	2
15610	Westmoreland County 67.3% Fayette County 32.7%	32.7%	2
15613	Westmoreland County 61.9% Armstrong County 38.1%	38.1%	2
15618	Armstrong County 63.1% Westmoreland County 29.4% Indiana County 7.5%	36.9%	3
15622	Fayette County 36.9% Somerset County 34.7% Westmoreland County 28.3%	63.1%	3
15642	Westmoreland County 98.1% Allegheny County 1.9%	1.9%	2
15656	Westmoreland County 57.5% Armstrong County 42.5%	42.5%	2
15666	Westmoreland County 76.1% Fayette County 23.9%	23.9%	2
15668	Westmoreland County 99.8% Allegheny County 0.2%	0.2%	2
15681	Indiana County 55.0% Westmoreland County 45.0%	45.0%	2
15683	Westmoreland County 81.1% Fayette County 18.9%	18.9%	2
15690	Armstrong County 90.7% Westmoreland County 9.3%	9.3%	2
15714	Cambria County 55.7% Indiana County 44.3%	44.3%	2
15717	Indiana County 69.7% Westmoreland County 30.3%	30.3%	2
15724	Indiana County 59.8% Clearfield County 29.0% Cambria County 11.3%	40.2%	3
15732	Indiana County 89.5% Armstrong County 10.5%	10.5%	2
15742	Indiana County 93.5% Clearfield County 6.5%	6.5%	2
15757	Clearfield County 94.6% Indiana County 5.4%	5.4%	2
15767	Jefferson County 83.6% Indiana County 9.2% Clearfield County 7.2%	16.4%	3
15772	Indiana County 96.5% Jefferson County 3.5%	3.5%	2
15774	Armstrong County 53.3% Indiana County 46.7%	46.7%	2
15801	Clearfield County 99.2% Jefferson County 0.8%	0.8%	2
15823	Elk County 84.9% Jefferson County 15.1%	15.1%	2
15824	Jefferson County 94.2% Clearfield County 5.8%	5.8%	2
15828	Forest County 57.5% Jefferson County 42.5%	42.5%	2
15829	Jefferson County 68.9% Clarion County 31.1%	31.1%	2
15832	Cameron County 89.3% Elk County 10.7%	10.7%	2
15840	Jefferson County 97.0% Clearfield County 3.0%	3.0%	2
15853	Elk County 93.6% Jefferson County 6.4%	6.4%	2
15860	Jefferson County 52.6% Elk County 45.1% Clarion County 2.3%	47.4%	3
15864	Jefferson County 56.2% Clarion County 43.8%	43.8%	2
15865	Jefferson County 78.7% Clearfield County 21.3%	21.3%	2
15870	Elk County 94.1% McKean County 5.9%	5.9%	2
15904	Cambria County 100.0% Somerset County under 0.1%	under 0.1%	2
15905	Cambria County 58.9% Somerset County 41.1%	41.1%	2
15944	Westmoreland County 64.1% Indiana County 35.9%	35.9%	2
15946	Cambria County 69.4% Blair County 21.1% Bedford County 9.4%	30.6%	3
15954	Indiana County 60.4% Westmoreland County 39.6%	39.6%	2
15957	Indiana County 53.9% Cambria County 46.1%	46.1%	2
15961	Indiana County 57.1% Cambria County 42.9%	42.9%	2
15963	Somerset County 74.3% Cambria County 25.8%	25.8%	2
16025	Butler County 88.2% Armstrong County 11.8%	11.8%	2
16028	Armstrong County 94.8% Clarion County 5.2%	5.2%	2
16037	Butler County 86.3% Lawrence County 7.8% Beaver County 5.8%	13.7%	3
16038	Butler County 62.4% Venango County 37.6%	37.6%	2
16041	Butler County 61.3% Armstrong County 38.7%	38.7%	2
16046	Butler County 80.4% Allegheny County 19.6%	19.6%	2
16049	Clarion County 45.8% Butler County 43.1% Armstrong County 11.1%	54.2%	3
16051	Butler County 59.5% Lawrence County 40.5%	40.5%	2
16055	Butler County 88.5% Armstrong County 11.5% Allegheny County under 0.1%	11.6%	3
16057	Butler County 86.3% Lawrence County 12.6% Mercer County 1.1%	13.7%	3
16059	Butler County 96.6% Allegheny County 3.4%	3.4%	2
16063	Butler County 77.9% Beaver County 22.1%	22.1%	2
16110	Crawford County 76.0% Mercer County 24.0%	24.0%	2
16117	Lawrence County 65.6% Beaver County 34.4%	34.4%	2
16120	Lawrence County 89.5% Beaver County 10.5%	10.5%	2
16123	Beaver County 82.0% Lawrence County 18.1%	18.1%	2
16125	Mercer County 98.4% Crawford County 1.6%	1.6%	2
16127	Mercer County 90.0% Venango County 8.0% Lawrence County 1.7% Butler County 0.3%	10.0%	4
16134	Crawford County 54.0% Mercer County 46.0%	46.0%	2
16141	Lawrence County 69.7% Beaver County 30.3%	30.3%	2
16142	Mercer County 62.4% Lawrence County 37.6%	37.6%	2
16143	Lawrence County 70.7% Mercer County 29.3%	29.3%	2
16153	Mercer County 86.5% Venango County 13.5%	13.5%	2
16156	Lawrence County 78.6% Mercer County 21.4%	21.4%	2
16157	Lawrence County 81.8% Beaver County 18.2%	18.2%	2
16159	Mercer County 89.5% Lawrence County 10.5%	10.5%	2
16217	Forest County 75.6% Clarion County 24.4%	24.4%	2
16222	Armstrong County 82.9% Indiana County 8.9% Jefferson County 8.2%	17.1%	3
16224	Clarion County 95.1% Armstrong County 4.9%	4.9%	2
16229	Armstrong County 88.0% Butler County 7.1% Westmoreland County 4.8%	12.0%	3
16232	Clarion County 98.7% Venango County 1.3%	1.3%	2
16240	Jefferson County 36.7% Armstrong County 35.9% Clarion County 27.4%	63.3%	3
16242	Clarion County 50.3% Armstrong County 49.7%	49.7%	2
16260	Clarion County 60.4% Forest County 39.6%	39.6%	2
16311	Mercer County 95.4% Venango County 4.6%	4.6%	2
16314	Crawford County 80.6% Mercer County 11.4% Venango County 8.0%	19.4%	3
16317	Venango County 95.3% Crawford County 4.7%	4.7%	2
16319	Venango County 75.2% Clarion County 24.8%	24.8%	2
16327	Crawford County 99.6% Venango County 0.4%	0.4%	2
16341	Venango County 68.3% Forest County 31.8%	31.8%	2
16342	Venango County 96.6% Mercer County 3.4%	3.4%	2
16347	Warren County 57.1% Forest County 42.9%	42.9%	2
16351	Warren County 86.5% Forest County 13.5%	13.5%	2
16353	Forest County 80.3% Clarion County 10.1% Venango County 9.5%	19.7%	3
16354	Venango County 51.6% Crawford County 40.7% Warren County 7.7%	48.4%	3
16362	Venango County 88.7% Mercer County 11.3%	11.3%	2
16364	Venango County 79.9% Clarion County 20.1%	20.1%	2
16373	Venango County 64.7% Clarion County 28.3% Butler County 7.0%	35.3%	3
16401	Erie County 95.8% Crawford County 4.3%	4.3%	2
16403	Crawford County 93.1% Erie County 6.9%	6.9%	2
16407	Erie County 72.4% Warren County 24.0% Crawford County 3.6%	27.6%	3
16412	Erie County 79.1% Crawford County 20.9%	20.9%	2
16434	Crawford County 83.0% Warren County 17.0%	17.0%	2
16435	Crawford County 99.5% Erie County 0.5%	0.5%	2
16438	Erie County 69.0% Crawford County 31.0%	31.0%	2
16441	Erie County 97.1% Crawford County 2.9%	2.9%	2
16613	Cambria County 68.1% Blair County 31.9%	31.9%	2
16625	Blair County 58.1% Bedford County 41.9%	41.9%	2
16627	Clearfield County 87.3% Cambria County 12.7%	12.7%	2
16636	Cambria County 95.0% Blair County 5.0%	5.0%	2
16639	Cambria County 88.8% Clearfield County 11.3%	11.3%	2
16641	Cambria County 93.2% Blair County 6.8%	6.8%	2
16646	Cambria County 98.6% Clearfield County 1.4%	1.4%	2
16655	Bedford County 97.9% Blair County 2.1%	2.1%	2
16657	Huntingdon County 98.0% Bedford County 2.0%	2.0%	2
16662	Blair County 84.9% Bedford County 15.1%	15.1%	2
16666	Clearfield County 89.3% Centre County 10.8%	10.8%	2
16673	Blair County 62.2% Bedford County 37.8%	37.8%	2
16678	Bedford County 55.3% Huntingdon County 44.7%	44.7%	2
16686	Blair County 68.5% Huntingdon County 24.8% Centre County 6.8%	31.5%	3
16694	Huntingdon County 84.5% Bedford County 14.1% Fulton County 1.4%	15.6%	3
16701	McKean County 94.5% Warren County 5.5%	5.5%	2
16720	Potter County 85.3% Cameron County 10.5% McKean County 4.2%	14.7%	3
16735	McKean County 60.6% Elk County 39.4%	39.4%	2
16743	McKean County 88.4% Potter County 11.6%	11.6%	2
16748	Potter County 76.7% McKean County 23.3%	23.3%	2
16822	Clinton County 95.8% Centre County 4.2%	4.2%	2
16841	Centre County 98.8% Clinton County 1.2%	1.2%	2
16845	Centre County 64.0% Clearfield County 36.0%	36.0%	2
16860	Clearfield County 76.6% Centre County 23.4%	23.4%	2
16865	Centre County 84.3% Huntingdon County 15.7%	15.7%	2
16866	Centre County 90.6% Clearfield County 9.4%	9.4%	2
16871	Clinton County 74.2% Clearfield County 25.8%	25.8%	2
16877	Centre County 58.7% Huntingdon County 41.3%	41.3%	2
16914	Bradford County 93.2% Tioga County 6.8%	6.8%	2
16921	Tioga County 98.7% Potter County 1.3%	1.3%	2
16930	Tioga County 74.7% Lycoming County 25.3%	25.3%	2
16936	Tioga County 82.9% Bradford County 17.1%	17.1%	2
16938	Tioga County 72.8% Lycoming County 27.2%	27.2%	2
16943	Potter County 58.7% Tioga County 41.3%	41.3%	2
16947	Bradford County 87.2% Tioga County 12.8%	12.8%	2
16950	Tioga County 83.3% Potter County 16.7%	16.7%	2
17002	Huntingdon County 82.3% Mifflin County 17.7%	17.7%	2
17011	Cumberland County 93.7% York County 6.3%	6.3%	2
17017	Northumberland County 78.3% Dauphin County 21.8%	21.8%	2
17019	York County 92.4% Cumberland County 6.2% Adams County 1.4%	7.6%	3
17020	Perry County 96.9% Dauphin County 3.1%	3.1%	2
17021	Juniata County 77.2% Perry County 15.8% Franklin County 5.4% Huntingdon County 1.6%	22.8%	4
17022	Lancaster County 70.8% Dauphin County 29.2%	29.2%	2
17026	Lebanon County 91.2% Berks County 8.8%	8.8%	2
17028	Lebanon County 53.9% Dauphin County 46.1%	46.1%	2
17033	Dauphin County 87.6% Lebanon County 12.4%	12.4%	2
17035	Juniata County 93.9% Perry County 6.1%	6.1%	2
17045	Perry County 67.1% Juniata County 25.6% Snyder County 7.3%	32.9%	3
17053	Perry County 99.3% Cumberland County 0.7%	0.7%	2
17055	Cumberland County 87.6% York County 12.4%	12.4%	2
17060	Huntingdon County 92.9% Mifflin County 7.1%	7.1%	2
17062	Perry County 76.3% Juniata County 23.7%	23.7%	2
17063	Mifflin County 94.1% Snyder County 5.9%	5.9%	2
17066	Huntingdon County 82.4% Mifflin County 17.6%	17.6%	2
17067	Lebanon County 73.5% Berks County 26.5%	26.5%	2
17070	York County 86.5% Cumberland County 13.5%	13.5%	2
17073	Lebanon County 90.6% Lancaster County 9.4%	9.4%	2
17078	Lebanon County 83.6% Dauphin County 16.4%	16.4%	2
17086	Snyder County 64.1% Juniata County 35.9%	35.9%	2
17087	Berks County 68.0% Lebanon County 32.0%	32.0%	2
17215	Huntingdon County 59.1% Fulton County 40.9%	40.9%	2
17222	Franklin County 69.0% Adams County 31.0%	31.0%	2
17224	Franklin County 95.1% Fulton County 4.9%	4.9%	2
17229	Fulton County 90.4% Huntingdon County 9.6%	9.6%	2
17236	Franklin County 95.3% Fulton County 4.7%	4.7%	2
17240	Cumberland County 60.8% Franklin County 39.2%	39.2%	2
17243	Huntingdon County 71.6% Juniata County 28.4%	28.4%	2
17255	Huntingdon County 94.5% Fulton County 5.5%	5.5%	2
17257	Cumberland County 63.6% Franklin County 36.4%	36.4%	2
17264	Huntingdon County 91.6% Fulton County 8.4%	8.4%	2
17301	Adams County 60.5% York County 39.5%	39.5%	2
17307	Adams County 90.6% Cumberland County 9.4%	9.4%	2
17316	Adams County 57.6% York County 42.4%	42.4%	2
17324	Cumberland County 65.1% Adams County 34.9%	34.9%	2
17331	York County 60.2% Adams County 39.8%	39.8%	2
17372	Adams County 98.7% York County 1.3%	1.3%	2
17527	Lancaster County 94.1% Chester County 5.9%	5.9%	2
17545	Lancaster County 94.1% Lebanon County 5.9%	5.9%	2
17555	Lancaster County 99.0% Chester County 0.9% Berks County under 0.1%	1.0%	3
17569	Lancaster County 73.9% Berks County 26.1%	26.1%	2
17701	Lycoming County 89.8% Sullivan County 10.2%	10.2%	2
17724	Bradford County 75.1% Tioga County 16.8% Lycoming County 8.1%	24.9%	3
17727	Tioga County 58.9% Lycoming County 41.1%	41.1%	2
17729	Potter County 71.3% Clinton County 28.7%	28.7%	2
17737	Lycoming County 98.4% Sullivan County 1.6%	1.6%	2
17740	Lycoming County 82.9% Clinton County 17.1%	17.1%	2
17745	Clinton County 71.7% Lycoming County 28.4%	28.4%	2
17756	Lycoming County 81.6% Northumberland County 13.5% Montour County 2.9% Columbia County 2.0%	18.4%	4
17758	Sullivan County 95.0% Lycoming County 5.0%	5.0%	2
17765	Tioga County 56.8% Lycoming County 42.4% Bradford County 0.7%	43.2%	3
17772	Montour County 68.6% Northumberland County 31.4%	31.4%	2
17774	Lycoming County 99.2% Columbia County 0.8%	0.8%	2
17777	Northumberland County 96.9% Montour County 3.1%	3.1%	2
17810	Lycoming County 73.8% Union County 26.2%	26.2%	2
17814	Columbia County 55.7% Sullivan County 25.5% Luzerne County 16.8% Lycoming County 2.0%	44.3%	4
17815	Columbia County 97.3% Luzerne County 2.4% Montour County 0.3%	2.7%	3
17820	Columbia County 94.1% Montour County 5.9%	5.9%	2
17821	Montour County 70.5% Northumberland County 23.5% Columbia County 6.0%	29.5%	3
17824	Columbia County 54.6% Northumberland County 43.9% Montour County 1.5%	45.4%	3
17841	Mifflin County 53.8% Snyder County 46.2%	46.2%	2
17846	Columbia County 96.4% Lycoming County 3.6%	3.6%	2
17847	Northumberland County 79.9% Montour County 20.1%	20.1%	2
17853	Snyder County 81.8% Juniata County 18.2%	18.2%	2
17870	Snyder County 97.9% Union County 2.1%	2.1%	2
17878	Columbia County 70.8% Luzerne County 29.3%	29.3%	2
17889	Snyder County 58.7% Union County 41.3%	41.3%	2
17921	Schuylkill County 91.4% Columbia County 8.6%	8.6%	2
17941	Schuylkill County 63.7% Northumberland County 36.3%	36.3%	2
17945	Columbia County 97.4% Schuylkill County 2.6%	2.6%	2
17963	Schuylkill County 96.4% Lebanon County 3.6%	3.6%	2
17964	Schuylkill County 89.7% Northumberland County 10.3%	10.3%	2
17978	Dauphin County 60.5% Schuylkill County 39.5%	39.5%	2
17980	Dauphin County 67.6% Schuylkill County 32.4%	32.4%	2
17985	Schuylkill County 57.8% Columbia County 42.2%	42.2%	2
18011	Berks County 76.9% Lehigh County 23.1%	23.1%	2
18015	Northampton County 65.5% Lehigh County 34.5%	34.5%	2
18017	Northampton County 94.8% Lehigh County 5.2%	5.2%	2
18018	Lehigh County 66.3% Northampton County 33.8%	33.8%	2
18031	Lehigh County 98.7% Berks County 1.3%	1.3%	2
18032	Lehigh County 64.3% Northampton County 35.7%	35.7%	2
18036	Lehigh County 62.3% Bucks County 37.7%	37.7%	2
18041	Montgomery County 64.1% Lehigh County 28.0% Bucks County 4.9% Berks County 3.0%	35.9%	4
18042	Northampton County 99.3% Bucks County 0.7%	0.7%	2
18054	Montgomery County 80.0% Bucks County 20.0%	20.0%	2
18055	Northampton County 94.3% Bucks County 5.7%	5.7%	2
18058	Monroe County 84.4% Carbon County 15.6%	15.6%	2
18062	Lehigh County 69.8% Berks County 30.3%	30.3%	2
18070	Montgomery County 60.7% Berks County 39.3%	39.3%	2
18071	Carbon County 96.9% Monroe County 3.1%	3.1%	2
18073	Montgomery County 84.9% Bucks County 15.1%	15.1%	2
18077	Bucks County 93.1% Northampton County 6.9%	6.9%	2
18092	Lehigh County 92.5% Berks County 7.5%	7.5%	2
18109	Lehigh County 94.9% Northampton County 5.1%	5.1%	2
18201	Luzerne County 97.6% Carbon County 2.4%	2.4%	2
18202	Luzerne County 88.7% Schuylkill County 11.3%	11.3%	2
18210	Carbon County 93.6% Monroe County 6.4%	6.4%	2
18211	Schuylkill County 96.3% Carbon County 3.7%	3.7%	2
18216	Carbon County 73.4% Luzerne County 26.6%	26.6%	2
18237	Schuylkill County 94.3% Carbon County 5.7%	5.7%	2
18240	Carbon County 87.2% Schuylkill County 12.8%	12.8%	2
18241	Luzerne County 96.9% Schuylkill County 3.1%	3.1%	2
18250	Carbon County 77.8% Schuylkill County 22.1%	22.1%	2
18255	Carbon County 88.8% Luzerne County 11.2%	11.2%	2
18302	Monroe County 99.2% Pike County 0.8%	0.8%	2
18324	Pike County 99.4% Monroe County 0.6%	0.6%	2
18325	Monroe County 72.6% Pike County 27.4%	27.4%	2
18326	Monroe County 97.3% Pike County 2.7%	2.7%	2
18405	Wayne County 76.3% Pike County 23.7%	23.7%	2
18407	Lackawanna County 92.5% Susquehanna County 7.5%	7.5%	2
18414	Lackawanna County 69.9% Wyoming County 30.1%	30.1%	2
18419	Wyoming County 64.1% Lackawanna County 32.8% Susquehanna County 3.1%	35.9%	3
18421	Susquehanna County 46.8% Wayne County 45.3% Lackawanna County 7.9%	53.2%	3
18424	Lackawanna County 69.0% Wayne County 19.4% Monroe County 9.9% Luzerne County 1.8%	31.0%	4
18426	Pike County 99.7% Wayne County 0.3%	0.3%	2
18428	Pike County 75.8% Wayne County 24.2%	24.2%	2
18436	Wayne County 72.6% Lackawanna County 27.4%	27.4%	2
18444	Lackawanna County 86.1% Wayne County 13.9%	13.9%	2
18445	Wayne County 67.8% Pike County 32.2%	32.2%	2
18446	Susquehanna County 56.8% Wyoming County 35.6% Lackawanna County 7.6%	43.2%	3
18462	Wayne County 85.0% Susquehanna County 15.0%	15.0%	2
18465	Susquehanna County 84.7% Wayne County 15.3%	15.3%	2
18466	Monroe County 97.7% Wayne County 2.3%	2.3%	2
18470	Susquehanna County 81.4% Wayne County 18.6%	18.6%	2
18603	Columbia County 58.0% Luzerne County 42.0%	42.0%	2
18610	Monroe County 95.5% Luzerne County 4.5%	4.5%	2
18612	Luzerne County 89.1% Wyoming County 10.9%	10.9%	2
18614	Sullivan County 75.9% Wyoming County 22.6% Bradford County 1.5%	24.1%	3
18615	Wyoming County 92.8% Luzerne County 7.2%	7.2%	2
18616	Sullivan County 87.2% Bradford County 12.8%	12.8%	2
18618	Luzerne County 60.9% Wyoming County 39.1%	39.1%	2
18619	Sullivan County 81.6% Lycoming County 18.4%	18.4%	2
18623	Bradford County 45.3% Wyoming County 35.9% Susquehanna County 18.8%	54.7%	3
18630	Susquehanna County 64.3% Wyoming County 35.7%	35.7%	2
18635	Luzerne County 60.2% Columbia County 39.8%	39.8%	2
18636	Wyoming County 88.4% Luzerne County 11.6%	11.6%	2
18641	Luzerne County 80.3% Lackawanna County 19.7%	19.7%	2
18655	Luzerne County 90.4% Columbia County 9.6%	9.6%	2
18661	Luzerne County 67.4% Carbon County 32.6%	32.6%	2
18829	Bradford County 98.6% Susquehanna County 1.4%	1.4%	2
18830	Susquehanna County 93.8% Bradford County 6.3%	6.3%	2
18833	Bradford County 92.2% Sullivan County 7.8%	7.8%	2
18844	Susquehanna County 98.9% Wyoming County 1.1%	1.1%	2
18846	Bradford County 99.6% Wyoming County 0.4%	0.4%	2
18847	Susquehanna County 79.9% Wayne County 20.1%	20.1%	2
18914	Bucks County 98.6% Montgomery County 1.4%	1.4%	2
18951	Bucks County 99.6% Lehigh County 0.4%	0.4%	2
18964	Montgomery County 88.6% Bucks County 11.4%	11.4%	2
18969	Montgomery County 81.0% Bucks County 19.0%	19.0%	2
19003	Delaware County 53.9% Montgomery County 46.1%	46.1%	2
19006	Montgomery County 91.0% Bucks County 9.0%	9.0%	2
19010	Delaware County 55.2% Montgomery County 44.8%	44.8%	2
19040	Montgomery County 98.7% Bucks County 1.3%	1.3%	2
19041	Delaware County 67.7% Montgomery County 32.3%	32.3%	2
19073	Delaware County 78.6% Chester County 21.4%	21.4%	2
19083	Delaware County 99.6% Montgomery County 0.4%	0.4%	2
19085	Delaware County 56.8% Montgomery County 43.2%	43.2%	2
19087	Chester County 50.0% Delaware County 34.7% Montgomery County 15.3%	50.0%	3
19096	Montgomery County 95.2% Delaware County 4.8%	4.8%	2
19118	Philadelphia County 98.2% Montgomery County 1.8%	1.8%	2
19128	Philadelphia County 97.6% Montgomery County 2.4%	2.4%	2
19153	Philadelphia County 71.3% Delaware County 28.7%	28.7%	2
19310	Chester County 92.5% Lancaster County 7.5%	7.5%	2
19312	Chester County 95.8% Delaware County 4.2%	4.2%	2
19317	Chester County 56.8% Delaware County 43.2%	43.2%	2
19319	Delaware County 74.5% Chester County 25.6%	25.6%	2
19342	Delaware County 96.7% Chester County 3.3%	3.3%	2
19344	Chester County 97.3% Lancaster County 2.6%	2.6%	2
19362	Chester County 61.4% Lancaster County 38.6%	38.6%	2
19363	Chester County 96.3% Lancaster County 3.7%	3.7%	2
19373	Delaware County 96.0% Chester County 4.0%	4.0%	2
19382	Chester County 97.4% Delaware County 2.6%	2.6%	2
19440	Montgomery County 75.2% Bucks County 24.8%	24.8%	2
19454	Montgomery County 99.1% Bucks County 0.9%	0.9%	2
19460	Chester County 81.6% Montgomery County 18.4%	18.4%	2
19464	Montgomery County 99.2% Berks County 0.8%	0.8%	2
19501	Lancaster County 98.0% Berks County 2.0%	2.0%	2
19504	Berks County 71.5% Montgomery County 28.5%	28.5%	2
19505	Berks County 92.8% Montgomery County 7.2%	7.2%	2
19512	Berks County 98.5% Montgomery County 1.5%	1.5%	2
19520	Chester County 77.0% Berks County 23.0%	23.0%	2
19525	Montgomery County 99.8% Berks County 0.2%	0.2%	2
19529	Berks County 66.1% Lehigh County 33.9%	33.9%	2
19530	Berks County 90.4% Lehigh County 9.6%	9.6%	2
19539	Berks County 94.8% Lehigh County 5.2%	5.2%	2
19540	Berks County 90.0% Lancaster County 10.0%	10.0%	2
19543	Berks County 68.4% Lancaster County 29.3% Chester County 2.3%	31.6%	3
19551	Berks County 82.0% Lebanon County 17.2% Lancaster County 0.8%	18.0%	3

What to do with this

If a ZIP code in your list is split, the ZIP alone cannot tell you which county an address is in. For most work that is fine. It matters when the county decides something: a sales tax rate, a licence, a franchise agreement written by county, or a service area somebody promised by county name.

The ZIP list audit checks your own list against the same Census data in your browser, and the ZIP spreadsheet comparison covers when a ZIP list is enough and when it is not.

What these numbers are, and are not

A ZCTA is not quite a ZIP code. ZIP Code Tabulation Areas are the Census Bureau's approximations of ZIP code areas, built by grouping census blocks by the ZIP codes of the addresses in them. USPS ZIP codes are delivery routes, not areas, and the two do not always match.
Some ZIP codes have no ZCTA at all. PO box ZIPs, ZIPs for a single building or a single large organisation, and military ZIPs usually have no area of their own, so they cannot be split across counties here and will not match any area in a map.
Land share is not population share. A ZCTA with 20% of its land in a second county might have almost none of its people there, or most of them. The shares here measure area, which is what the Census file publishes.
Tiny overlaps are included. A ZCTA counts as overlapping a county if the Census file lists any part of it there, including slivers along a road or river. That is why the share with at least 5% of land in a second county is shown alongside.

Source: U.S. Census Bureau, 2020 ZCTA to County relationship file, public domain. Counts use 2020 ZCTAs and 2020 county boundaries. ZIP codes added by USPS since then are not in it, and Connecticut's counties have since been replaced by planning regions in Census data.

Route by the boundary, not the ZIP

MapLogics decides who owns an address from a boundary you draw or import, so a ZIP that straddles two counties is answered by where the address actually is. There is a free trial if you want to see it on your own addresses.

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