ZIP codes and county lines in Illinois

486 of the 1397 ZIP code areas in Illinois, or 34.8%, 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: 1,397
In more than one county: 486
At least 5% in a second county: 366
Cross a state line: 1

How Illinois compares

Illinois ranks 22 of 52 (the 50 states, DC and Puerto Rico) by the share of its ZIP code areas that overlap more than one county. 102 of its counties have at least one split ZIP code area along an edge. 1 of its ZIP code areas also reach into Missouri, so a ZIP list that is meant to stop at the state line does not.

Counties with the most split ZIP code areas

Will County: 28 ZIP codes shared with another county
Cook County: 23 ZIP codes shared with another county
Montgomery County: 20 ZIP codes shared with another county
DuPage County: 19 ZIP codes shared with another county
Kane County: 19 ZIP codes shared with another county

Every split ZIP code area in Illinois

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
60007	Cook County 96.0% DuPage County 4.0%	4.0%	2
60010	Cook County 50.7% Lake County 38.1% McHenry County 9.4% Kane County 1.7%	49.3%	4
60013	McHenry County 91.1% Lake County 8.9%	8.9%	2
60015	Lake County 96.2% Cook County 3.8%	3.8%	2
60020	Lake County 99.1% McHenry County 0.9%	0.9%	2
60021	McHenry County 93.8% Lake County 6.2%	6.2%	2
60033	McHenry County 94.1% Boone County 5.9%	5.9%	2
60042	Lake County 53.8% McHenry County 46.2%	46.2%	2
60050	McHenry County 99.6% Lake County 0.4%	0.4%	2
60051	McHenry County 81.6% Lake County 18.4%	18.4%	2
60074	Cook County 94.7% Lake County 5.3%	5.3%	2
60081	McHenry County 81.6% Lake County 18.4%	18.4%	2
60089	Lake County 78.4% Cook County 21.6%	21.6%	2
60090	Cook County 99.5% Lake County 0.5%	0.5%	2
60102	McHenry County 77.8% Kane County 22.2%	22.2%	2
60103	DuPage County 65.6% Cook County 33.8% Kane County 0.6%	34.4%	3
60120	Cook County 72.3% Kane County 27.7%	27.7%	2
60126	DuPage County 97.3% Cook County 2.8%	2.8%	2
60129	Ogle County 72.7% DeKalb County 27.3%	27.3%	2
60133	DuPage County 64.1% Cook County 35.9%	35.9%	2
60135	DeKalb County 96.2% McHenry County 2.2% Boone County 1.6%	3.8%	3
60140	Kane County 94.6% DeKalb County 4.2% McHenry County 1.2%	5.4%	3
60142	McHenry County 72.5% Kane County 27.5%	27.5%	2
60145	DeKalb County 94.6% Boone County 5.4%	5.4%	2
60146	DeKalb County 88.0% Boone County 10.0% Ogle County 1.9%	12.0%	3
60151	Kane County 75.4% DeKalb County 24.6%	24.6%	2
60152	McHenry County 98.0% DeKalb County 2.0%	2.0%	2
60172	DuPage County 82.6% Cook County 17.4%	17.4%	2
60174	Kane County 98.7% DuPage County 1.3%	1.3%	2
60178	DeKalb County 93.3% Kane County 6.7%	6.7%	2
60184	DuPage County 64.4% Kane County 35.6%	35.6%	2
60185	DuPage County 96.4% Kane County 3.6%	3.6%	2
60401	Will County 98.0% Kankakee County 2.0%	2.0%	2
60407	Grundy County 79.3% Will County 20.7%	20.7%	2
60410	Will County 83.3% Grundy County 16.7%	16.7%	2
60416	Grundy County 96.5% Will County 3.5%	3.5%	2
60420	Livingston County 71.6% Grundy County 28.4%	28.4%	2
60423	Will County 94.7% Cook County 5.3%	5.3%	2
60424	Grundy County 94.7% Kankakee County 5.3%	5.3%	2
60431	Will County 73.7% Kendall County 26.3%	26.3%	2
60439	Cook County 67.3% DuPage County 24.1% Will County 8.6%	32.6%	3
60440	Will County 98.1% DuPage County 1.9%	1.9%	2
60447	Kendall County 73.0% Grundy County 21.4% Will County 5.6%	27.0%	3
60449	Will County 98.7% Cook County 1.3%	1.3%	2
60450	Grundy County 97.8% Kendall County 2.2%	2.2%	2
60466	Cook County 72.7% Will County 27.3%	27.3%	2
60467	Cook County 94.0% Will County 6.0%	6.0%	2
60468	Will County 95.3% Kankakee County 4.7%	4.7%	2
60470	LaSalle County 91.7% Livingston County 4.4% Grundy County 4.0%	8.3%	3
60471	Cook County 95.5% Will County 4.5%	4.5%	2
60475	Cook County 68.5% Will County 31.5%	31.5%	2
60477	Cook County 96.3% Will County 3.6%	3.6%	2
60481	Will County 97.2% Kankakee County 2.4% Grundy County 0.4%	2.9%	3
60487	Cook County 59.0% Will County 41.0%	41.0%	2
60502	DuPage County 59.3% Kane County 40.7%	40.7%	2
60503	Will County 72.3% Kendall County 27.7%	27.7%	2
60504	DuPage County 79.6% Kane County 19.6% Kendall County 0.8%	20.4%	3
60506	Kane County 99.2% Kendall County 0.8%	0.8%	2
60510	Kane County 83.5% DuPage County 16.5%	16.5%	2
60511	Kane County 96.2% DeKalb County 3.8%	3.8%	2
60517	DuPage County 90.5% Will County 9.5%	9.5%	2
60518	LaSalle County 66.2% DeKalb County 25.1% Lee County 8.7%	33.8%	3
60521	DuPage County 82.8% Cook County 17.2%	17.2%	2
60523	DuPage County 99.8% Cook County 0.2%	0.2%	2
60527	DuPage County 79.3% Cook County 20.7%	20.7%	2
60530	Lee County 68.4% DeKalb County 31.6%	31.6%	2
60531	LaSalle County 62.2% DeKalb County 37.8%	37.8%	2
60537	LaSalle County 68.5% Kendall County 31.5%	31.5%	2
60538	Kendall County 53.7% Kane County 46.3%	46.3%	2
60541	Kendall County 89.8% Grundy County 9.3% LaSalle County 0.9%	10.3%	3
60543	Kendall County 99.2% Will County 0.6% Kane County 0.2%	0.8%	3
60544	Will County 74.1% Kendall County 25.9%	25.9%	2
60548	DeKalb County 54.1% LaSalle County 33.9% Kendall County 12.0%	45.9%	3
60552	DeKalb County 81.3% LaSalle County 18.7%	18.7%	2
60554	Kane County 98.2% Kendall County 1.8%	1.8%	2
60564	Will County 75.3% DuPage County 24.8%	24.8%	2
60565	DuPage County 63.1% Will County 36.9%	36.9%	2
60585	Will County 88.1% Kendall County 11.9%	11.9%	2
60586	Will County 73.3% Kendall County 26.7%	26.7%	2
60917	Kankakee County 79.5% Livingston County 16.3% Ford County 4.2%	20.5%	3
60918	Iroquois County 98.0% Ford County 2.0%	2.0%	2
60919	Ford County 44.2% Livingston County 41.5% Kankakee County 14.2%	55.8%	3
60921	Livingston County 96.8% Ford County 3.2%	3.2%	2
60922	Kankakee County 51.3% Iroquois County 48.7%	48.7%	2
60929	Livingston County 88.7% Ford County 11.3%	11.3%	2
60936	Ford County 92.8% McLean County 5.3% Champaign County 1.8%	7.2%	3
60940	Kankakee County 97.6% Will County 2.4%	2.4%	2
60941	Kankakee County 84.4% Iroquois County 11.7% Ford County 3.9%	15.6%	3
60942	Vermilion County 68.3% Iroquois County 31.7%	31.7%	2
60946	Ford County 82.4% Livingston County 17.6%	17.6%	2
60948	Iroquois County 70.1% Ford County 29.9%	29.9%	2
60949	Champaign County 93.1% Ford County 6.9%	6.9%	2
60950	Kankakee County 93.6% Will County 6.4%	6.4%	2
60952	Ford County 94.2% Livingston County 5.8%	5.8%	2
60957	Ford County 85.5% Champaign County 14.6%	14.6%	2
60959	Ford County 95.1% Livingston County 4.9%	4.9%	2
60960	Vermilion County 66.6% Ford County 22.4% Iroquois County 8.9% Champaign County 2.1%	33.4%	4
60961	Kankakee County 68.4% Livingston County 26.1% Grundy County 5.4%	31.6%	3
60964	Kankakee County 72.0% Iroquois County 28.0%	28.0%	2
60968	Iroquois County 52.3% Ford County 45.6% Livingston County 2.1%	47.7%	3
61006	Lee County 73.3% Ogle County 26.7%	26.7%	2
61007	Ogle County 56.7% Stephenson County 43.3%	43.3%	2
61008	Boone County 99.9% Winnebago County 0.1%	0.1%	2
61011	Boone County 82.0% Winnebago County 18.0%	18.0%	2
61014	Carroll County 85.0% Whiteside County 15.0%	15.0%	2
61016	Winnebago County 56.8% Boone County 43.2%	43.2%	2
61019	Stephenson County 62.0% Winnebago County 38.0%	38.0%	2
61020	Ogle County 90.6% Winnebago County 9.4%	9.4%	2
61021	Lee County 89.6% Ogle County 10.4%	10.4%	2
61028	Jo Daviess County 99.7% Carroll County 0.3%	0.3%	2
61031	Lee County 95.0% Ogle County 5.0%	5.0%	2
61038	Boone County 92.8% McHenry County 7.2%	7.2%	2
61039	Stephenson County 62.0% Ogle County 38.0%	38.0%	2
61044	Stephenson County 65.7% Jo Daviess County 34.3%	34.3%	2
61047	Ogle County 92.3% Winnebago County 6.0% Stephenson County 1.7%	7.7%	3
61048	Stephenson County 91.2% Jo Daviess County 8.8%	8.8%	2
61051	Carroll County 96.1% Ogle County 3.9%	3.9%	2
61053	Carroll County 90.3% Jo Daviess County 9.7%	9.7%	2
61062	Stephenson County 91.1% Jo Daviess County 6.6% Carroll County 2.3%	8.9%	3
61063	Winnebago County 83.7% Stephenson County 16.4%	16.4%	2
61064	Ogle County 93.9% Carroll County 4.3% Lee County 1.0% Whiteside County 0.7%	6.1%	4
61068	Ogle County 88.8% Lee County 10.0% DeKalb County 1.2%	11.2%	3
61071	Whiteside County 89.0% Lee County 11.0%	11.0%	2
61073	Winnebago County 95.8% Boone County 4.2%	4.2%	2
61074	Carroll County 98.1% Jo Daviess County 1.9%	1.9%	2
61078	Carroll County 66.2% Stephenson County 17.5% Ogle County 16.3%	33.8%	3
61080	Winnebago County 71.2% Boone County 28.8%	28.8%	2
61081	Whiteside County 94.7% Lee County 5.3%	5.3%	2
61084	Ogle County 93.0% Winnebago County 7.0%	7.0%	2
61087	Jo Daviess County 93.0% Stephenson County 7.0%	7.0%	2
61088	Winnebago County 99.8% Ogle County 0.2%	0.2%	2
61089	Stephenson County 96.0% Jo Daviess County 4.0%	4.0%	2
61102	Winnebago County 88.2% Ogle County 11.8%	11.8%	2
61107	Winnebago County 94.3% Boone County 5.7%	5.7%	2
61109	Winnebago County 96.7% Ogle County 3.3%	3.3%	2
61111	Winnebago County 95.7% Boone County 4.3%	4.3%	2
61114	Winnebago County 87.8% Boone County 12.2%	12.2%	2
61240	Rock Island County 54.1% Henry County 45.9%	45.9%	2
61243	Whiteside County 95.4% Lee County 4.6%	4.6%	2
61250	Whiteside County 94.1% Henry County 5.9%	5.9%	2
61254	Henry County 99.5% Whiteside County 0.5%	0.5%	2
61259	Rock Island County 96.8% Mercer County 3.2%	3.2%	2
61262	Henry County 94.5% Mercer County 5.5%	5.5%	2
61264	Rock Island County 98.0% Mercer County 2.0%	2.0%	2
61270	Whiteside County 99.0% Carroll County 1.0%	1.0%	2
61272	Mercer County 96.9% Rock Island County 3.1%	3.1%	2
61273	Henry County 75.6% Rock Island County 24.0% Mercer County 0.3%	24.4%	3
61277	Whiteside County 59.9% Henry County 40.1%	40.1%	2
61279	Mercer County 53.1% Rock Island County 46.9%	46.9%	2
61281	Mercer County 82.9% Rock Island County 17.1%	17.1%	2
61283	Whiteside County 50.7% Bureau County 47.0% Henry County 2.4%	49.3%	3
61321	LaSalle County 96.8% Marshall County 3.2%	3.2%	2
61330	Bureau County 91.8% Lee County 8.2%	8.2%	2
61334	LaSalle County 99.3% Putnam County 0.7%	0.7%	2
61336	Putnam County 55.9% Marshall County 44.1%	44.1%	2
61342	LaSalle County 86.9% Bureau County 8.1% Lee County 5.0%	13.1%	3
61344	Bureau County 94.9% Henry County 5.1%	5.1%	2
61345	Bureau County 92.0% Stark County 8.0%	8.0%	2
61349	Bureau County 73.3% Lee County 26.8%	26.8%	2
61354	LaSalle County 91.9% Bureau County 8.1%	8.1%	2
61358	LaSalle County 53.6% Marshall County 46.4%	46.4%	2
61360	LaSalle County 78.7% Grundy County 21.3%	21.3%	2
61361	Bureau County 90.4% Henry County 9.6%	9.6%	2
61364	LaSalle County 78.3% Livingston County 21.7%	21.7%	2
61376	Bureau County 85.6% Lee County 14.4%	14.4%	2
61377	LaSalle County 50.2% Marshall County 49.8%	49.8%	2
61401	Knox County 79.7% Warren County 20.3%	20.3%	2
61410	Knox County 72.4% Warren County 27.6%	27.6%	2
61412	Mercer County 54.9% Warren County 45.1%	45.1%	2
61414	Knox County 78.6% Henry County 21.4%	21.4%	2
61415	Fulton County 62.8% Warren County 37.2%	37.2%	2
61420	McDonough County 81.1% Hancock County 18.9%	18.9%	2
61421	Stark County 54.6% Bureau County 36.4% Marshall County 9.0%	45.4%	3
61434	Henry County 74.3% Knox County 24.9% Stark County 0.8%	25.6%	3
61440	McDonough County 82.9% Schuyler County 17.1%	17.1%	2
61442	Mercer County 79.3% Henderson County 20.6%	20.6%	2
61443	Henry County 94.0% Stark County 3.5% Bureau County 2.5%	6.0%	3
61447	Warren County 69.0% Henderson County 31.0%	31.0%	2
61449	Stark County 69.1% Knox County 30.9%	30.9%	2
61450	Hancock County 89.3% Henderson County 7.0% McDonough County 3.7%	10.7%	3
61452	Schuyler County 95.8% McDonough County 4.2%	4.2%	2
61453	Warren County 58.4% Henderson County 41.6%	41.6%	2
61459	Fulton County 84.6% McDonough County 15.4%	15.4%	2
61462	Warren County 96.1% Henderson County 3.9%	3.9%	2
61465	Mercer County 84.3% Henry County 15.7%	15.7%	2
61472	Knox County 98.7% Mercer County 1.3%	1.3%	2
61474	Knox County 76.1% Warren County 17.4% Fulton County 6.5%	23.9%	3
61475	McDonough County 86.0% Warren County 12.1% Henderson County 1.9%	14.0%	3
61476	Mercer County 71.8% Henderson County 28.2%	28.2%	2
61478	Warren County 85.9% Henderson County 14.1%	14.1%	2
61479	Marshall County 51.0% Stark County 49.0%	49.0%	2
61482	Fulton County 88.2% McDonough County 11.8%	11.8%	2
61484	Fulton County 54.0% McDonough County 41.4% Schuyler County 4.6%	46.0%	3
61489	Knox County 96.5% Peoria County 3.5%	3.5%	2
61490	Henry County 86.9% Knox County 13.1%	13.1%	2
61491	Stark County 89.2% Marshall County 10.8%	10.8%	2
61523	Peoria County 93.6% Marshall County 6.4%	6.4%	2
61526	Peoria County 91.8% Marshall County 8.2%	8.2%	2
61529	Peoria County 97.6% Knox County 2.4%	2.4%	2
61530	Woodford County 95.9% Tazewell County 4.1%	4.1%	2
61531	Fulton County 62.9% Knox County 23.3% Peoria County 13.8%	37.1%	3
61533	Peoria County 82.9% Fulton County 17.1%	17.1%	2
61537	Marshall County 94.7% Bureau County 5.3%	5.3%	2
61544	Fulton County 70.4% Knox County 29.6%	29.6%	2
61546	Tazewell County 63.3% Mason County 36.7%	36.7%	2
61559	Peoria County 90.8% Stark County 9.2%	9.2%	2
61560	Putnam County 92.0% Marshall County 4.2% Bureau County 3.8%	8.1%	3
61565	Marshall County 98.9% Peoria County 1.1%	1.1%	2
61569	Peoria County 98.3% Fulton County 1.7%	1.7%	2
61570	Woodford County 55.9% Marshall County 44.1%	44.1%	2
61611	Tazewell County 70.6% Woodford County 29.4%	29.4%	2
61720	McLean County 87.2% Ford County 12.8%	12.8%	2
61721	Tazewell County 85.7% Logan County 14.3%	14.3%	2
61723	Logan County 91.8% McLean County 8.2%	8.2%	2
61725	Woodford County 52.6% McLean County 47.4%	47.4%	2
61726	McLean County 64.6% Livingston County 35.4%	35.4%	2
61729	Woodford County 93.9% McLean County 6.1%	6.1%	2
61731	McLean County 46.5% Livingston County 41.2% Ford County 12.3%	53.5%	3
61732	McLean County 91.2% Tazewell County 8.8%	8.8%	2
61733	Tazewell County 84.0% Woodford County 16.1%	16.1%	2
61738	Woodford County 94.0% McLean County 6.0%	6.0%	2
61739	Livingston County 95.3% McLean County 4.7%	4.7%	2
61742	Woodford County 95.5% Tazewell County 4.5%	4.5%	2
61744	McLean County 59.5% Livingston County 37.9% Woodford County 2.6%	40.5%	3
61745	McLean County 82.3% De Witt County 17.7%	17.7%	2
61748	McLean County 96.7% Woodford County 3.3%	3.3%	2
61749	De Witt County 79.9% Macon County 10.8% Logan County 9.3%	20.1%	3
61752	McLean County 94.8% De Witt County 5.2%	5.2%	2
61754	McLean County 87.3% De Witt County 7.8% Logan County 4.8%	12.7%	3
61756	Macon County 70.3% De Witt County 29.7%	29.7%	2
61760	Woodford County 92.3% Marshall County 7.7%	7.7%	2
61810	Vermilion County 58.0% Edgar County 22.0% Champaign County 20.0%	42.0%	3
61818	Piatt County 85.5% Macon County 14.5%	14.5%	2
61830	Piatt County 72.0% Macon County 28.0%	28.0%	2
61842	De Witt County 63.4% Piatt County 18.7% McLean County 17.9%	36.6%	3
61843	Champaign County 94.4% McLean County 5.6%	5.6%	2
61845	Champaign County 90.0% Ford County 10.0%	10.0%	2
61849	Champaign County 66.3% Vermilion County 33.8%	33.8%	2
61851	Champaign County 89.3% Piatt County 10.7%	10.7%	2
61852	Champaign County 78.9% Douglas County 21.1%	21.1%	2
61853	Champaign County 92.0% Piatt County 8.0%	8.0%	2
61854	Piatt County 94.7% McLean County 5.3%	5.3%	2
61859	Champaign County 85.4% Vermilion County 14.6%	14.6%	2
61862	Champaign County 81.6% Vermilion County 18.4%	18.4%	2
61870	Vermilion County 85.7% Edgar County 14.3%	14.3%	2
61872	Champaign County 90.2% Douglas County 9.8%	9.8%	2
61875	Champaign County 98.8% Piatt County 1.2%	1.2%	2
61876	Vermilion County 75.4% Edgar County 24.6%	24.6%	2
61882	De Witt County 90.0% Piatt County 7.4% Macon County 2.6%	10.0%	3
61884	Piatt County 79.3% Champaign County 20.7%	20.7%	2
61910	Douglas County 67.2% Coles County 32.8%	32.8%	2
61911	Moultrie County 47.0% Douglas County 41.2% Coles County 11.7%	53.0%	3
61913	Piatt County 48.2% Douglas County 47.9% Moultrie County 4.0%	51.8%	3
61914	Moultrie County 75.8% Shelby County 20.9% Macon County 3.3%	24.2%	3
61917	Edgar County 93.6% Douglas County 6.4%	6.4%	2
61925	Macon County 74.7% Moultrie County 25.3%	25.3%	2
61928	Moultrie County 62.6% Shelby County 32.2% Coles County 5.2%	37.4%	3
61929	Piatt County 99.5% Moultrie County 0.5%	0.5%	2
61930	Douglas County 76.4% Coles County 23.6%	23.6%	2
61933	Edgar County 92.8% Clark County 6.3% Coles County 0.9%	7.2%	3
61937	Moultrie County 92.8% Macon County 7.2%	7.2%	2
61938	Coles County 98.7% Cumberland County 1.3% Moultrie County under 0.1%	1.3%	3
61942	Douglas County 90.5% Edgar County 9.5%	9.5%	2
61943	Coles County 57.9% Douglas County 34.2% Edgar County 7.9%	42.1%	3
61944	Edgar County 99.2% Clark County 0.8%	0.8%	2
61951	Moultrie County 97.6% Coles County 2.4%	2.4%	2
61956	Douglas County 77.0% Champaign County 23.0%	23.0%	2
61957	Shelby County 87.3% Moultrie County 12.7%	12.7%	2
62002	Madison County 92.8% Macoupin County 7.2%	7.2%	2
62012	Jersey County 50.0% Macoupin County 44.6% Madison County 5.4%	50.0%	3
62017	Montgomery County 93.8% Bond County 6.2%	6.2%	2
62019	Bond County 66.3% Montgomery County 33.8%	33.8%	2
62021	Madison County 97.7% Macoupin County 2.3%	2.3%	2
62032	Montgomery County 97.0% Fayette County 3.0%	3.0%	2
62035	Madison County 69.6% Jersey County 30.4%	30.4%	2
62044	Greene County 80.7% Macoupin County 19.3%	19.3%	2
62052	Jersey County 98.8% Greene County 1.2%	1.2%	2
62054	Greene County 65.7% Jersey County 34.3%	34.3%	2
62056	Montgomery County 72.0% Macoupin County 28.0%	28.0%	2
62060	Madison County 95.1% St. Clair County 4.9%	4.9%	2
62063	Jersey County 51.7% Macoupin County 47.8% Greene County 0.5%	48.3%	3
62069	Macoupin County 97.3% Montgomery County 2.7%	2.7%	2
62074	Madison County 75.0% Bond County 13.3% Macoupin County 8.0% Montgomery County 3.7%	25.0%	4
62075	Montgomery County 81.0% Christian County 18.4% Fayette County 0.6%	18.9%	3
62077	Montgomery County 54.5% Bond County 45.5%	45.5%	2
62079	Macoupin County 81.5% Jersey County 18.5%	18.5%	2
62080	Fayette County 94.2% Montgomery County 3.9% Shelby County 1.9%	5.8%	3
62082	Greene County 83.0% Scott County 16.2% Morgan County 0.8%	17.0%	3
62083	Christian County 61.7% Montgomery County 38.3%	38.3%	2
62086	Bond County 76.3% Montgomery County 20.8% Madison County 2.9%	23.8%	3
62088	Macoupin County 63.5% Madison County 36.5%	36.5%	2
62201	St. Clair County 96.0% Madison County 4.0%	4.0%	2
62216	Clinton County 92.0% Madison County 8.0%	8.0%	2
62234	Madison County 83.3% St. Clair County 16.8%	16.8%	2
62236	Monroe County 82.0% St. Clair County 18.0%	18.0%	2
62237	Perry County 49.5% Washington County 25.5% Randolph County 25.0%	50.5%	3
62249	Madison County 90.2% Clinton County 7.5% Bond County 2.3%	9.8%	3
62253	Bond County 80.5% Fayette County 12.2% Clinton County 7.3%	19.5%	3
62254	St. Clair County 98.3% Madison County 1.7%	1.7%	2
62257	St. Clair County 56.9% Washington County 36.1% Randolph County 7.0%	43.1%	3
62262	Bond County 60.6% Fayette County 39.4%	39.4%	2
62263	Washington County 99.2% Perry County 0.8%	0.8%	2
62264	St. Clair County 94.5% Monroe County 5.5%	5.5%	2
62265	Clinton County 86.4% St. Clair County 13.6%	13.6%	2
62268	Washington County 95.2% Perry County 4.8%	4.8%	2
62272	Randolph County 81.9% Perry County 16.9% Jackson County 1.1%	18.1%	3
62274	Perry County 99.1% Jackson County 0.9%	0.9%	2
62275	Bond County 76.1% Madison County 17.4% Clinton County 6.4%	23.9%	3
62277	Randolph County 60.7% Monroe County 39.3%	39.3%	2
62278	Monroe County 54.0% Randolph County 46.0%	46.0%	2
62280	Jackson County 57.0% Randolph County 43.0%	43.0%	2
62293	Clinton County 46.4% St. Clair County 37.2% Madison County 16.4%	53.6%	3
62294	Madison County 97.2% St. Clair County 2.8%	2.8%	2
62298	Monroe County 90.9% St. Clair County 9.1%	9.1%	2
62311	Hancock County 48.5% Schuyler County 40.0% Adams County 11.5%	51.5%	3
62312	Pike County 77.5% Adams County 22.4%	22.4%	2
62314	Pike County 84.6% Adams County 15.4%	15.4%	2
62316	Hancock County 89.1% Adams County 10.9%	10.9%	2
62323	Pike County 98.2% Brown County 1.8%	1.8%	2
62324	Adams County 92.9% Brown County 7.1%	7.1%	2
62326	McDonough County 95.0% Hancock County 5.0%	5.0%	2
62330	Hancock County 90.8% Henderson County 9.2%	9.2%	2
62343	Pike County 94.3% Adams County 5.7%	5.7%	2
62346	Adams County 62.0% Schuyler County 38.0%	38.0%	2
62349	Adams County 90.5% Hancock County 9.5%	9.5%	2
62351	Adams County 95.1% Hancock County 4.9%	4.9%	2
62353	Brown County 98.1% Pike County 1.2% Schuyler County 0.7%	1.9%	3
62355	Pike County 54.8% Calhoun County 45.2%	45.2%	2
62367	Hancock County 37.7% McDonough County 34.4% Schuyler County 27.9%	62.3%	3
62373	Hancock County 96.5% Adams County 3.5%	3.5%	2
62374	Hancock County 50.9% McDonough County 49.1%	49.1%	2
62379	Hancock County 80.4% Adams County 19.6%	19.6%	2
62401	Effingham County 97.2% Shelby County 2.8%	2.8%	2
62411	Effingham County 96.6% Fayette County 3.4%	3.4%	2
62413	Crawford County 91.0% Clark County 9.0%	9.0%	2
62414	Fayette County 54.4% Effingham County 26.5% Shelby County 19.1%	45.6%	3
62420	Clark County 56.9% Cumberland County 36.1% Coles County 5.5% Jasper County 1.6%	43.1%	4
62421	Richland County 92.6% Crawford County 6.0% Lawrence County 1.4%	7.4%	3
62422	Shelby County 65.0% Fayette County 35.0%	35.0%	2
62423	Clark County 66.4% Edgar County 33.6%	33.6%	2
62424	Effingham County 91.2% Jasper County 7.5% Clay County 1.2%	8.8%	3
62425	Richland County 83.1% Jasper County 16.9%	16.9%	2
62426	Clay County 55.8% Effingham County 31.9% Fayette County 12.3%	44.2%	3
62427	Crawford County 76.2% Lawrence County 23.8%	23.8%	2
62431	Shelby County 62.3% Fayette County 37.7%	37.7%	2
62432	Jasper County 99.7% Cumberland County 0.3%	0.3%	2
62434	Clay County 61.3% Jasper County 38.7%	38.7%	2
62436	Cumberland County 61.8% Jasper County 38.2%	38.2%	2
62440	Coles County 73.8% Cumberland County 26.2%	26.2%	2
62441	Clark County 96.3% Edgar County 3.7%	3.7%	2
62442	Clark County 97.9% Crawford County 2.1%	2.1%	2
62443	Effingham County 89.4% Clay County 10.6%	10.6%	2
62445	Jasper County 46.9% Cumberland County 42.5% Effingham County 10.6%	53.1%	3
62447	Cumberland County 69.0% Shelby County 31.0% Coles County under 0.1%	31.0%	3
62448	Jasper County 96.6% Richland County 2.3% Clay County 1.1%	3.4%	3
62449	Crawford County 81.4% Jasper County 17.6% Clark County 1.0%	18.6%	3
62450	Richland County 99.5% Wayne County 0.6%	0.6%	2
62458	Fayette County 87.7% Effingham County 12.3%	12.3%	2
62460	Lawrence County 98.2% Wabash County 1.8%	1.8%	2
62461	Effingham County 70.7% Shelby County 29.3%	29.3%	2
62462	Shelby County 49.9% Cumberland County 49.8% Effingham County 0.3%	50.1%	3
62466	Lawrence County 88.8% Crawford County 8.8% Richland County 2.4%	11.2%	3
62467	Effingham County 80.4% Jasper County 10.5% Cumberland County 9.1%	19.6%	3
62469	Cumberland County 85.0% Coles County 15.0%	15.0%	2
62474	Clark County 63.6% Coles County 36.4%	36.4%	2
62476	Edwards County 68.6% Wabash County 29.3% Lawrence County 1.3% Richland County 0.8%	31.4%	4
62478	Clark County 53.7% Crawford County 46.3%	46.3%	2
62479	Jasper County 98.1% Effingham County 1.9%	1.9%	2
62510	Christian County 51.3% Shelby County 48.7%	48.7%	2
62512	Logan County 97.8% De Witt County 2.2%	2.2%	2
62513	Christian County 52.2% Macon County 47.8%	47.8%	2
62534	Shelby County 99.7% Moultrie County 0.3%	0.3%	2
62538	Montgomery County 80.7% Christian County 19.3%	19.3%	2
62539	Sangamon County 76.8% Macon County 23.1%	23.1%	2
62543	Logan County 65.2% Macon County 34.8%	34.8%	2
62545	Sangamon County 64.7% Christian County 35.3%	35.3%	2
62546	Christian County 89.4% Montgomery County 10.6%	10.6%	2
62547	Christian County 96.3% Macon County 3.7%	3.7%	2
62548	Logan County 98.7% Sangamon County 1.3%	1.3%	2
62550	Shelby County 59.6% Christian County 33.8% Macon County 6.5%	40.4%	3
62553	Shelby County 80.5% Montgomery County 19.5%	19.5%	2
62557	Christian County 73.8% Shelby County 21.2% Montgomery County 5.0%	26.2%	3
62558	Sangamon County 52.9% Christian County 38.0% Montgomery County 9.2%	47.1%	3
62560	Montgomery County 88.8% Macoupin County 11.2%	11.2%	2
62563	Sangamon County 95.8% Christian County 4.2%	4.2%	2
62572	Montgomery County 50.9% Macoupin County 49.1%	49.1%	2
62611	Cass County 65.7% Morgan County 34.4%	34.4%	2
62612	Cass County 61.9% Morgan County 38.1%	38.1%	2
62613	Menard County 85.4% Sangamon County 7.3% Logan County 7.3%	14.6%	3
62621	Scott County 93.0% Morgan County 7.0%	7.0%	2
62627	Cass County 62.4% Mason County 37.6%	37.6%	2
62628	Morgan County 87.2% Scott County 12.8%	12.8%	2
62630	Macoupin County 94.5% Greene County 5.5%	5.5%	2
62635	Logan County 91.2% Tazewell County 8.8%	8.8%	2
62638	Morgan County 95.6% Macoupin County 4.4%	4.4%	2
62640	Macoupin County 96.9% Montgomery County 3.1%	3.1%	2
62644	Mason County 67.9% Fulton County 32.1%	32.1%	2
62650	Morgan County 98.2% Scott County 1.8%	1.8%	2
62665	Morgan County 75.5% Scott County 24.5%	24.5%	2
62666	Logan County 76.9% Menard County 23.1%	23.1%	2
62667	Macoupin County 94.9% Morgan County 5.1%	5.1%	2
62668	Morgan County 87.2% Scott County 12.8%	12.8%	2
62670	Sangamon County 92.1% Morgan County 7.9%	7.9%	2
62671	Logan County 89.5% Mason County 10.5%	10.5%	2
62673	Menard County 69.3% Cass County 30.7%	30.7%	2
62675	Menard County 98.0% Cass County 2.0%	2.0%	2
62677	Sangamon County 98.3% Menard County 1.7%	1.7%	2
62682	Mason County 56.0% Logan County 30.1% Tazewell County 13.9%	44.0%	3
62690	Macoupin County 62.7% Montgomery County 21.1% Sangamon County 16.2%	37.3%	3
62692	Morgan County 52.3% Sangamon County 47.7%	47.7%	2
62693	Sangamon County 60.6% Logan County 36.5% Menard County 2.9%	39.4%	3
62694	Scott County 97.7% Morgan County 2.3%	2.3%	2
62801	Marion County 37.0% Clinton County 33.3% Washington County 15.8% Jefferson County 13.8%	63.0%	4
62808	Washington County 68.5% Jefferson County 31.5%	31.5%	2
62810	Jefferson County 85.6% Wayne County 9.9% Hamilton County 4.5%	14.4%	3
62814	Jefferson County 82.1% Wayne County 17.9%	17.9%	2
62818	Edwards County 50.1% Wabash County 49.9%	49.9%	2
62820	White County 59.7% Wayne County 40.3%	40.3%	2
62824	Clay County 84.5% Wayne County 15.5%	15.5%	2
62828	Hamilton County 97.1% Wayne County 2.9%	2.9%	2
62830	Jefferson County 95.9% Marion County 4.1%	4.1%	2
62831	Washington County 76.9% Perry County 23.1%	23.1%	2
62832	Perry County 94.8% Jackson County 5.2%	5.2%	2
62833	Wayne County 70.7% Edwards County 29.3%	29.3%	2
62835	White County 82.1% Hamilton County 17.9%	17.9%	2
62836	Franklin County 93.1% Jefferson County 6.9%	6.9%	2
62838	Fayette County 61.5% Clay County 29.2% Marion County 7.9% Effingham County 1.4%	38.5%	4
62844	White County 62.2% Edwards County 37.8%	37.8%	2
62851	Wayne County 90.0% Jefferson County 7.6% Marion County 2.4%	10.0%	3
62854	Marion County 98.2% Clay County 1.1% Fayette County 0.7%	1.8%	3
62858	Clay County 98.8% Effingham County 1.2%	1.2%	2
62859	Hamilton County 99.5% Franklin County 0.5%	0.5%	2
62860	Franklin County 72.0% Hamilton County 28.0%	28.0%	2
62867	White County 65.2% Gallatin County 34.8%	34.8%	2
62868	Richland County 67.1% Clay County 16.8% Wayne County 16.2%	32.9%	3
62869	White County 93.7% Hamilton County 3.5% Saline County 2.2% Gallatin County 0.6%	6.3%	4
62871	Gallatin County 98.9% White County 1.1%	1.1%	2
62875	Marion County 57.4% Fayette County 35.4% Clinton County 7.2%	42.6%	3
62877	Washington County 93.5% Jefferson County 6.5%	6.5%	2
62882	Marion County 82.8% Clinton County 17.2%	17.2%	2
62883	Jefferson County 70.5% Perry County 16.0% Franklin County 13.4%	29.5%	3
62887	White County 52.4% Hamilton County 47.6%	47.6%	2
62889	Jefferson County 67.7% Marion County 32.3%	32.3%	2
62890	Franklin County 52.4% Williamson County 23.2% Hamilton County 16.3% Saline County 8.1%	47.6%	4
62892	Marion County 90.4% Fayette County 9.6%	9.6%	2
62893	Jefferson County 55.0% Marion County 45.0%	45.0%	2
62895	Wayne County 75.6% Hamilton County 24.4%	24.4%	2
62896	Franklin County 90.9% Williamson County 9.1%	9.1%	2
62899	Clay County 59.1% Wayne County 40.9%	40.9%	2
62901	Jackson County 89.3% Williamson County 10.7%	10.7%	2
62902	Williamson County 63.6% Jackson County 34.9% Union County 1.5%	36.4%	3
62905	Union County 83.0% Jackson County 17.0%	17.0%	2
62907	Jackson County 99.0% Randolph County 1.0%	1.0%	2
62908	Massac County 64.6% Johnson County 35.4%	35.4%	2
62910	Massac County 55.5% Pope County 44.5%	44.5%	2
62912	Johnson County 59.3% Union County 40.7%	40.7%	2
62916	Jackson County 47.5% Perry County 30.1% Randolph County 22.3%	52.5%	3
62917	Saline County 78.4% Williamson County 21.6%	21.6%	2
62918	Williamson County 99.9% Jackson County under 0.1%	under 0.1%	2
62920	Union County 95.8% Jackson County 4.2%	4.2%	2
62922	Williamson County 73.5% Johnson County 26.6%	26.6%	2
62923	Johnson County 59.8% Union County 21.7% Pulaski County 18.5%	40.2%	3
62924	Jackson County 87.8% Williamson County 12.2%	12.2%	2
62926	Union County 77.8% Pulaski County 22.2%	22.2%	2
62930	Saline County 91.6% Gallatin County 4.8% Hamilton County 3.6%	8.4%	3
62931	Hardin County 91.8% Gallatin County 8.2%	8.2%	2
62932	Jackson County 98.4% Franklin County 1.6%	1.6%	2
62934	Gallatin County 66.5% Saline County 33.5%	33.5%	2
62935	Saline County 91.4% Hamilton County 7.8% Williamson County 0.8%	8.6%	3
62938	Pope County 94.0% Hardin County 4.2% Massac County 1.8%	6.0%	3
62939	Johnson County 89.6% Union County 6.5% Williamson County 4.0%	10.4%	3
62941	Pulaski County 73.8% Massac County 26.2%	26.2%	2
62943	Johnson County 60.5% Massac County 24.5% Pope County 15.0%	39.5%	3
62946	Saline County 94.8% Pope County 5.3%	5.3%	2
62947	Pope County 58.0% Hardin County 34.0% Saline County 8.0%	42.0%	3
62952	Union County 97.6% Alexander County 2.4%	2.4%	2
62956	Massac County 51.3% Pulaski County 48.8%	48.8%	2
62957	Alexander County 79.3% Union County 20.7%	20.7%	2
62958	Jackson County 39.9% Union County 37.1% Williamson County 23.0%	60.1%	3
62960	Massac County 98.3% Pope County 1.7%	1.7%	2
62967	Johnson County 96.4% Williamson County 3.6%	3.6%	2
62972	Johnson County 90.9% Pope County 9.1%	9.1%	2
62985	Pope County 63.6% Johnson County 36.4%	36.4%	2
62987	Pope County 43.1% Saline County 39.0% Williamson County 17.9%	56.9%	3
62992	Pulaski County 82.0% Alexander County 18.0%	18.0%	2
63673	Ste. Genevieve County, MO 49.5% Perry County, MO 30.2% Randolph County 20.3%	50.5%	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

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