ZIP codes and county lines in Nebraska

293 of the 592 ZIP code areas in Nebraska, or 49.5%, 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: 592
In more than one county: 293
At least 5% in a second county: 242
Cross a state line: 19

How Nebraska compares

Nebraska ranks 6 of 52 (the 50 states, DC and Puerto Rico) by the share of its ZIP code areas that overlap more than one county. 93 of its counties have at least one split ZIP code area along an edge. 19 of its ZIP code areas also reach into Colorado, Iowa, Kansas, South Dakota and Wyoming, so a ZIP list that is meant to stop at the state line does not.

Counties with the most split ZIP code areas

Custer County: 15 ZIP codes shared with another county
Lancaster County: 15 ZIP codes shared with another county
Cherry County: 14 ZIP codes shared with another county
Otoe County: 14 ZIP codes shared with another county
Seward County: 13 ZIP codes shared with another county

Every split ZIP code area in Nebraska

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
51557	Harrison County, IA 89.7% Burt County 10.3%	10.3%	2
57735	Fall River County, SD 77.4% Custer County, SD 20.7% Sioux County 1.9%	22.6%	3
66541	Marshall County, KS 72.0% Pawnee County 28.0%	28.0%	2
66955	Washington County, KS 77.9% Thayer County 22.1%	22.1%	2
68003	Saunders County 73.5% Cass County 26.5%	26.5%	2
68004	Cuming County 99.1% Burt County 0.9%	0.9%	2
68007	Douglas County 73.7% Washington County 26.3%	26.3%	2
68017	Saunders County 68.5% Lancaster County 31.5%	31.5%	2
68019	Burt County 96.9% Washington County 1.9% Dodge County 1.2%	3.1%	3
68020	Burt County 86.4% Thurston County 13.6%	13.6%	2
68025	Dodge County 73.1% Saunders County 26.7% Washington County 0.1%	26.9%	3
68029	Washington County 78.0% Burt County 22.0%	22.0%	2
68031	Dodge County 89.7% Washington County 10.3%	10.3%	2
68036	Butler County 77.1% Saunders County 22.9%	22.9%	2
68038	Burt County 94.8% Cuming County 2.8% Thurston County 2.4%	5.2%	3
68044	Dodge County 53.9% Washington County 46.1%	46.1%	2
68045	Burt County 79.0% Cuming County 20.0% Dodge County 1.1%	21.0%	3
68047	Thurston County 55.7% Cuming County 32.6% Wayne County 11.7%	44.3%	3
68057	Dodge County 99.0% Cuming County 1.0%	1.0%	2
68064	Douglas County 90.9% Saunders County 8.1% Dodge County 1.0%	9.1%	3
68065	Saunders County 64.1% Lancaster County 23.4% Seward County 6.8% Butler County 5.7%	35.9%	4
68069	Douglas County 89.3% Sarpy County 10.7%	10.7%	2
68112	Douglas County 57.2% Washington County 42.8%	42.8%	2
68122	Douglas County 79.2% Washington County 20.8%	20.8%	2
68142	Douglas County 73.1% Washington County 26.9%	26.9%	2
68147	Sarpy County 99.3% Douglas County 0.7%	0.7%	2
68152	Douglas County 84.8% Washington County 15.2%	15.2%	2
68157	Sarpy County 99.7% Douglas County 0.3%	0.3%	2
68301	Gage County 76.7% Lancaster County 17.1% Otoe County 6.2%	23.3%	3
68303	Thayer County 85.2% Jefferson County 14.8%	14.8%	2
68307	Cass County 54.2% Otoe County 45.8%	45.8%	2
68310	Gage County 97.4% Jefferson County 2.6%	2.6%	2
68313	Seward County 98.7% York County 1.3%	1.3%	2
68314	Seward County 94.8% Butler County 5.2%	5.2%	2
68316	York County 87.8% Polk County 12.2%	12.2%	2
68317	Lancaster County 87.7% Otoe County 12.3%	12.3%	2
68319	York County 98.6% Hamilton County 1.4%	1.4%	2
68322	Thayer County 70.7% Fillmore County 29.3%	29.3%	2
68324	Otoe County 90.5% Johnson County 9.5%	9.5%	2
68325	Thayer County 55.1% Republic County, KS 44.9%	44.9%	2
68326	Thayer County 94.5% Fillmore County 5.5%	5.5%	2
68327	Thayer County 65.9% Republic County, KS 34.1%	34.1%	2
68329	Johnson County 72.0% Otoe County 28.0%	28.0%	2
68333	Saline County 67.0% Lancaster County 33.0%	33.0%	2
68335	Thayer County 57.0% Nuckolls County 33.4% Fillmore County 9.6%	43.0%	3
68339	Lancaster County 86.6% Seward County 8.9% Saline County 4.5%	13.4%	3
68341	Gage County 51.7% Saline County 45.2% Jefferson County 3.1%	48.3%	3
68342	Jefferson County 73.8% Gage County 26.1%	26.1%	2
68343	Saline County 95.0% Seward County 5.0%	5.0%	2
68345	Pawnee County 65.0% Richardson County 35.0%	35.0%	2
68347	Cass County 65.9% Otoe County 34.1%	34.1%	2
68348	Johnson County 75.4% Pawnee County 13.3% Nemaha County 11.3%	24.6%	3
68351	Fillmore County 74.0% York County 26.0%	26.0%	2
68354	Fillmore County 87.0% York County 13.0%	13.0%	2
68357	Gage County 98.9% Johnson County 1.1%	1.1%	2
68358	Lancaster County 67.4% Gage County 32.6%	32.6%	2
68359	Saline County 85.5% Seward County 14.1% Fillmore County 0.4%	14.5%	3
68365	Fillmore County 97.3% York County 2.6%	2.6%	2
68366	Cass County 62.1% Lancaster County 32.7% Saunders County 5.1%	37.9%	3
68367	Polk County 36.4% York County 32.9% Seward County 30.7%	63.6%	3
68368	Lancaster County 89.7% Gage County 10.3%	10.3%	2
68371	York County 76.9% Hamilton County 23.1%	23.1%	2
68376	Richardson County 82.5% Nemaha County 10.3% Pawnee County 7.2%	17.6%	3
68378	Nemaha County 85.5% Johnson County 14.5%	14.5%	2
68379	Otoe County 93.0% Nemaha County 7.0%	7.0%	2
68381	Gage County 71.4% Pawnee County 28.6%	28.6%	2
68405	Seward County 99.0% Saline County 1.0%	1.0%	2
68406	Fillmore County 61.6% Saline County 38.4%	38.4%	2
68413	Cass County 85.5% Otoe County 14.6%	14.6%	2
68418	Otoe County 97.1% Cass County 2.9%	2.9%	2
68420	Pawnee County 97.6% Nemaha County, KS 2.4%	2.4%	2
68421	Nemaha County 94.2% Otoe County 5.8%	5.8%	2
68423	Seward County 96.3% Lancaster County 2.8% Saline County 0.9%	3.7%	3
68424	Jefferson County 98.6% Gage County 1.4%	1.4%	2
68428	Lancaster County 95.6% Seward County 4.4%	4.4%	2
68429	Jefferson County 52.2% Thayer County 47.8%	47.8%	2
68436	Fillmore County 95.6% Clay County 4.4%	4.4%	2
68437	Richardson County 62.0% Nemaha County 38.0%	38.0%	2
68441	Pawnee County 89.5% Johnson County 10.5%	10.5%	2
68442	Richardson County 80.1% Nemaha County 19.9%	19.9%	2
68443	Johnson County 98.4% Otoe County 1.6%	1.6%	2
68447	Pawnee County 89.3% Nemaha County 6.9% Johnson County 3.9%	10.8%	3
68448	Otoe County 80.6% Nemaha County 10.8% Johnson County 8.6%	19.4%	3
68453	Saline County 69.8% Fillmore County 19.6% Jefferson County 6.7% Thayer County 3.8%	30.1%	4
68454	Otoe County 98.3% Cass County 1.8%	1.8%	2
68455	Cass County 92.9% Otoe County 7.1%	7.1%	2
68458	Gage County 73.9% Pawnee County 17.4% Johnson County 8.7%	26.1%	3
68460	York County 96.8% Seward County 3.2%	3.2%	2
68462	Lancaster County 94.6% Cass County 5.4%	5.4%	2
68464	Saline County 97.7% Jefferson County 2.3%	2.3%	2
68465	Saline County 91.3% Gage County 6.0% Lancaster County 2.7%	8.7%	3
68527	Lancaster County 93.7% Cass County 6.3%	6.3%	2
68528	Lancaster County 99.0% Seward County 1.0%	1.0%	2
68601	Platte County 73.6% Colfax County 13.4% Polk County 11.1% Butler County 1.9%	26.4%	4
68623	Nance County 93.0% Boone County 7.0%	7.0%	2
68627	Boone County 84.7% Nance County 10.8% Greeley County 4.5%	15.3%	3
68628	Merrick County 76.5% Polk County 18.7% Hamilton County 4.8%	23.5%	3
68629	Colfax County 63.8% Stanton County 36.2%	36.2%	2
68631	Platte County 87.7% Stanton County 12.3%	12.3%	2
68633	Dodge County 48.0% Cuming County 32.2% Colfax County 19.8%	52.0%	3
68636	Antelope County 93.7% Wheeler County 6.3%	6.3%	2
68637	Wheeler County 55.2% Garfield County 25.2% Greeley County 19.6%	44.8%	3
68638	Nance County 97.9% Merrick County 2.1%	2.1%	2
68640	Nance County 75.3% Platte County 24.6%	24.6%	2
68641	Colfax County 52.2% Stanton County 25.7% Cuming County 22.1%	47.8%	3
68642	Platte County 83.5% Madison County 16.5%	16.5%	2
68643	Platte County 34.5% Stanton County 34.0% Colfax County 31.4%	65.5%	3
68644	Platte County 71.2% Madison County 28.8%	28.8%	2
68654	Polk County 62.9% York County 28.2% Hamilton County 8.9%	37.1%	3
68655	Boone County 83.1% Greeley County 16.9%	16.9%	2
68658	Butler County 98.6% Polk County 1.4%	1.4%	2
68660	Boone County 56.2% Platte County 28.1% Nance County 15.7%	43.8%	3
68662	Polk County 93.8% Butler County 6.2%	6.2%	2
68663	Merrick County 44.8% Polk County 30.3% Nance County 24.9%	55.2%	3
68665	Greeley County 67.0% Wheeler County 33.0%	33.0%	2
68666	Polk County 97.5% York County 2.5%	2.5%	2
68669	Butler County 90.0% Seward County 10.0%	10.0%	2
68701	Madison County 68.9% Stanton County 18.8% Pierce County 12.3%	31.1%	3
68714	Rock County 86.2% Loup County 11.8% Brown County 2.1%	13.8%	3
68719	Boyd County 61.1% Gregory County, SD 38.9%	38.9%	2
68725	Holt County 97.4% Wheeler County 2.6%	2.6%	2
68726	Antelope County 93.0% Holt County 7.0%	7.0%	2
68729	Knox County 82.0% Antelope County 18.0%	18.0%	2
68730	Knox County 67.7% Cedar County 32.3%	32.3%	2
68733	Thurston County 42.1% Dixon County 31.0% Dakota County 26.9%	57.9%	3
68735	Holt County 64.8% Wheeler County 30.4% Antelope County 4.8%	35.2%	3
68739	Cedar County 98.8% Dixon County 1.3%	1.3%	2
68740	Wayne County 93.5% Stanton County 6.5%	6.5%	2
68745	Cedar County 88.2% Wayne County 6.1% Dixon County 5.7%	11.8%	3
68746	Boyd County 61.7% Holt County 38.3%	38.3%	2
68747	Pierce County 96.1% Cedar County 3.9%	3.9%	2
68748	Madison County 82.8% Stanton County 17.2%	17.2%	2
68752	Madison County 75.9% Pierce County 24.1%	24.1%	2
68755	Boyd County 99.6% Gregory County, SD 0.4%	0.4%	2
68757	Dixon County 91.7% Cedar County 8.3%	8.3%	2
68758	Madison County 56.4% Platte County 24.6% Boone County 19.0%	43.6%	3
68759	Rock County 56.2% Keya Paha County 43.8%	43.8%	2
68763	Holt County 98.6% Knox County 1.4%	1.4%	2
68764	Antelope County 55.4% Knox County 35.9% Holt County 8.7%	44.6%	3
68767	Pierce County 98.8% Wayne County 1.2%	1.2%	2
68768	Stanton County 92.4% Wayne County 5.2% Cuming County 2.4%	7.6%	3
68769	Pierce County 64.1% Antelope County 35.5% Knox County 0.5%	35.9%	3
68770	Dixon County 94.3% Dakota County 5.7%	5.7%	2
68771	Cedar County 49.3% Pierce County 31.0% Wayne County 19.7%	50.7%	3
68777	Boyd County 72.0% Holt County 28.0%	28.0%	2
68781	Antelope County 54.5% Madison County 27.2% Pierce County 12.4% Boone County 5.8%	45.5%	4
68784	Dixon County 52.4% Wayne County 44.8% Thurston County 2.8%	47.6%	3
68785	Dixon County 51.5% Dakota County 48.5%	48.5%	2
68786	Knox County 78.7% Cedar County 17.2% Pierce County 4.1%	21.3%	3
68787	Wayne County 93.7% Dixon County 6.3%	6.3%	2
68788	Cuming County 99.9% Dodge County 0.1%	0.1%	2
68791	Cuming County 94.2% Wayne County 4.4% Stanton County 1.4%	5.8%	3
68801	Hall County 60.6% Merrick County 39.4%	39.4%	2
68813	Custer County 63.9% Blaine County 25.3% Loup County 10.8%	36.1%	3
68815	Valley County 55.5% Custer County 26.0% Sherman County 18.5%	44.5%	3
68817	Sherman County 85.8% Howard County 14.2%	14.2%	2
68818	Hamilton County 94.0% Clay County 6.0%	6.0%	2
68823	Garfield County 55.3% Loup County 23.3% Rock County 10.3% Valley County 6.0% Holt County 3.0% Custer County 2.2%	44.7%	6
68824	Hall County 86.2% Howard County 13.8%	13.8%	2
68828	Custer County 72.8% Valley County 27.2%	27.2%	2
68831	Howard County 96.0% Hall County 4.0%	4.0%	2
68832	Hall County 88.1% Hamilton County 11.9%	11.9%	2
68833	Blaine County 69.5% Custer County 23.9% Logan County 6.6%	30.6%	3
68834	Dawson County 69.0% Custer County 31.0%	31.0%	2
68835	Howard County 90.8% Greeley County 9.2%	9.2%	2
68836	Buffalo County 52.7% Phelps County 32.6% Dawson County 14.7%	47.3%	3
68840	Buffalo County 88.4% Kearney County 11.6%	11.6%	2
68843	Hamilton County 96.3% York County 3.7%	3.7%	2
68844	Sherman County 64.1% Buffalo County 35.9%	35.9%	2
68845	Buffalo County 78.6% Kearney County 12.4% Phelps County 9.0%	21.4%	3
68847	Buffalo County 80.2% Kearney County 19.8%	19.8%	2
68850	Dawson County 93.2% Gosper County 6.8%	6.8%	2
68852	Sherman County 86.5% Custer County 13.5%	13.5%	2
68858	Buffalo County 95.7% Custer County 4.3%	4.3%	2
68859	Valley County 88.3% Sherman County 11.7%	11.7%	2
68860	Custer County 96.8% Dawson County 3.2%	3.2%	2
68862	Valley County 95.0% Garfield County 5.0%	5.0%	2
68863	Dawson County 87.2% Phelps County 12.8%	12.8%	2
68864	Merrick County 38.4% Nance County 36.9% Howard County 24.7%	61.6%	3
68866	Buffalo County 94.4% Custer County 5.6%	5.6%	2
68869	Buffalo County 73.3% Sherman County 26.7%	26.7%	2
68872	Howard County 73.6% Merrick County 26.4%	26.4%	2
68874	Custer County 95.3% Loup County 4.7%	4.7%	2
68875	Greeley County 95.9% Howard County 4.1%	4.1%	2
68876	Buffalo County 72.0% Hall County 27.9%	27.9%	2
68878	Dawson County 78.4% Custer County 21.6%	21.6%	2
68882	Greeley County 67.7% Howard County 24.8% Nance County 7.6%	32.3%	3
68883	Hall County 95.2% Adams County 4.8%	4.8%	2
68901	Adams County 83.2% Clay County 14.3% Hall County 2.4%	16.8%	3
68922	Furnas County 53.6% Gosper County 46.4%	46.4%	2
68924	Kearney County 89.0% Phelps County 11.0%	11.0%	2
68927	Phelps County 64.8% Gosper County 35.2%	35.2%	2
68928	Webster County 82.7% Adams County 17.3%	17.3%	2
68930	Webster County 80.8% Adams County 19.2%	19.2%	2
68932	Franklin County 41.9% Webster County 32.6% Kearney County 12.8% Adams County 12.8%	58.1%	4
68934	Nuckolls County 68.8% Clay County 31.2%	31.2%	2
68935	Clay County 63.8% Nuckolls County 36.2%	36.2%	2
68936	Furnas County 63.7% Gosper County 36.3%	36.3%	2
68937	Gosper County 93.0% Dawson County 3.6% Frontier County 3.5%	7.0%	3
68941	Clay County 58.7% Adams County 41.3%	41.3%	2
68942	Webster County 72.9% Nuckolls County 27.1%	27.1%	2
68943	Nuckolls County 84.0% Republic County, KS 11.9% Thayer County 4.1%	16.0%	3
68944	Clay County 89.4% Hamilton County 10.6%	10.6%	2
68945	Kearney County 97.8% Adams County 2.1%	2.1%	2
68947	Franklin County 79.2% Kearney County 20.8%	20.8%	2
68948	Furnas County 48.7% Gosper County 30.8% Frontier County 20.5%	51.3%	3
68949	Phelps County 85.0% Harlan County 15.0%	15.0%	2
68956	Adams County 71.4% Kearney County 20.3% Hall County 6.5% Buffalo County 1.8%	28.6%	4
68957	Nuckolls County 68.5% Webster County 27.0% Adams County 2.7% Clay County 1.9%	31.6%	4
68960	Franklin County 98.2% Harlan County 1.8%	1.8%	2
68964	Nuckolls County 96.6% Thayer County 3.4%	3.4%	2
68967	Furnas County 48.8% Harlan County 47.6% Gosper County 3.6%	51.2%	3
68972	Franklin County 99.3% Webster County 0.7%	0.7%	2
68974	Nuckolls County 89.0% Thayer County 11.0%	11.0%	2
68977	Harlan County 50.9% Furnas County 49.1%	49.1%	2
68978	Nuckolls County 84.7% Jewell County, KS 15.3%	15.3%	2
68979	Clay County 64.3% Fillmore County 29.1% Hamilton County 5.2% York County 1.5%	35.7%	4
68980	Clay County 46.5% Adams County 26.6% Hamilton County 18.9% Hall County 8.0%	53.5%	4
68981	Franklin County 89.7% Kearney County 10.3%	10.3%	2
68982	Franklin County 30.4% Harlan County 29.7% Phelps County 27.4% Kearney County 12.5%	69.5%	4
69001	Red Willow County 66.5% Frontier County 25.1% Hayes County 5.4% Hitchcock County 3.0%	33.5%	4
69020	Red Willow County 83.0% Frontier County 17.0%	17.0%	2
69022	Frontier County 46.6% Furnas County 35.9% Red Willow County 17.5%	53.4%	3
69024	Hitchcock County 76.2% Hayes County 19.6% Red Willow County 2.8% Frontier County 1.5%	23.8%	4
69025	Frontier County 74.5% Lincoln County 25.5%	25.5%	2
69026	Red Willow County 64.3% Decatur County, KS 35.7%	35.7%	2
69027	Chase County 92.7% Dundy County 7.3%	7.3%	2
69028	Frontier County 67.5% Dawson County 24.7% Gosper County 7.8%	32.5%	3
69029	Frontier County 52.5% Lincoln County 29.0% Dawson County 18.5%	47.5%	3
69030	Dundy County 88.6% Chase County 11.4%	11.4%	2
69033	Chase County 96.1% Perkins County 3.9%	3.9%	2
69034	Red Willow County 78.7% Frontier County 21.3%	21.3%	2
69038	Frontier County 64.3% Hayes County 35.7%	35.7%	2
69039	Lincoln County 54.3% Frontier County 45.7%	45.7%	2
69040	Hayes County 51.5% Hitchcock County 48.5%	48.5%	2
69043	Hitchcock County 95.4% Dundy County 4.6%	4.6%	2
69045	Chase County 42.5% Hayes County 34.3% Dundy County 20.3% Hitchcock County 2.8%	57.5%	4
69046	Furnas County 88.3% Red Willow County 11.7%	11.7%	2
69101	Lincoln County 94.1% McPherson County 5.9%	5.9%	2
69120	Custer County 54.9% Logan County 24.6% Lincoln County 20.5%	45.1%	3
69122	Deuel County 59.6% Keith County 23.9% Perkins County 16.5%	40.4%	3
69127	Keith County 83.2% Perkins County 16.8%	16.8%	2
69128	Kimball County 88.8% Banner County 11.2%	11.2%	2
69129	Deuel County 80.5% Garden County 19.5%	19.5%	2
69130	Dawson County 93.0% Custer County 7.0%	7.0%	2
69131	Cheyenne County 63.1% Morrill County 36.9%	36.9%	2
69134	Perkins County 78.7% Chase County 11.1% Hayes County 10.2%	21.3%	3
69138	Dawson County 42.4% Custer County 33.4% Lincoln County 24.3%	57.6%	3
69142	Thomas County 100.0% Blaine County under 0.1%	under 0.1%	2
69144	Keith County 88.6% Arthur County 11.4%	11.4%	2
69145	Kimball County 82.0% Banner County 17.9%	17.9%	2
69146	Keith County 60.6% Arthur County 39.4%	39.4%	2
69147	Garden County 86.2% Keith County 12.4% Arthur County 1.5%	13.8%	3
69148	Garden County 75.0% Morrill County 25.0%	25.0%	2
69149	Cheyenne County 77.2% Garden County 18.5% Deuel County 4.3%	22.8%	3
69152	Hooker County 51.1% Cherry County 48.9%	48.9%	2
69153	Keith County 84.6% Perkins County 15.4%	15.4%	2
69155	Keith County 93.2% Perkins County 5.2% McPherson County 1.2% Arthur County 0.5%	6.8%	4
69156	Cheyenne County 62.3% Banner County 23.5% Kimball County 14.3%	37.7%	3
69157	Blaine County 71.3% Brown County 20.6% Cherry County 8.0%	28.6%	3
69161	Cherry County 64.9% Thomas County 35.1%	35.1%	2
69163	Logan County 62.6% Thomas County 19.7% Lincoln County 12.5% McPherson County 5.2%	37.4%	4
69165	Lincoln County 50.2% McPherson County 31.9% Arthur County 17.9%	49.8%	3
69166	Thomas County 52.3% Cherry County 47.7%	47.7%	2
69168	Perkins County 61.3% Chase County 34.3% Sedgwick County, CO 4.4%	38.7%	3
69169	Lincoln County 77.6% Perkins County 16.5% Hayes County 6.0%	22.4%	3
69201	Cherry County 83.1% Todd County, SD 16.9%	16.9%	2
69212	Cherry County 57.1% Todd County, SD 42.9%	42.9%	2
69214	Brown County 94.2% Cherry County 5.8%	5.8%	2
69216	Cherry County 70.9% Todd County, SD 29.1%	29.1%	2
69217	Brown County 85.3% Rock County 14.7%	14.7%	2
69220	Keya Paha County 66.1% Cherry County 33.9%	33.9%	2
69301	Box Butte County 59.8% Sheridan County 23.2% Morrill County 17.0%	40.2%	3
69333	Grant County 42.9% Cherry County 40.1% Garden County 16.5% Sheridan County 0.5%	57.1%	4
69334	Morrill County 83.0% Scotts Bluff County 11.0% Banner County 6.0%	17.0%	3
69335	Sheridan County 61.3% Garden County 38.7%	38.7%	2
69336	Morrill County 97.1% Banner County 2.9%	2.9%	2
69337	Dawes County 79.0% Oglala Lakota County, SD 11.4% Sheridan County 6.5% Fall River County, SD 3.1%	21.0%	4
69339	Dawes County 67.3% Sioux County 32.6%	32.6%	2
69340	Sheridan County 76.2% Garden County 17.4% Cherry County 6.4%	23.8%	3
69341	Scotts Bluff County 81.6% Banner County 18.4%	18.4%	2
69343	Cherry County 60.0% Sheridan County 40.0%	40.0%	2
69347	Sheridan County 82.3% Dawes County 17.7%	17.7%	2
69348	Box Butte County 70.1% Dawes County 15.9% Sioux County 14.0%	29.9%	3
69350	Grant County 63.6% Cherry County 30.6% Arthur County 5.8%	36.4%	3
69351	Sheridan County 60.2% Garden County 39.8%	39.8%	2
69354	Sioux County 50.3% Dawes County 34.1% Box Butte County 15.6%	49.7%	3
69357	Sioux County 68.5% Scotts Bluff County 31.5%	31.5%	2
69358	Sioux County 71.8% Scotts Bluff County 28.2%	28.2%	2
69361	Sioux County 57.0% Scotts Bluff County 43.0%	43.0%	2
69366	Cherry County 58.1% Grant County 39.7% Arthur County 2.2%	41.9%	3
80737	Sedgwick County, CO 96.2% Deuel County 3.8%	3.8%	2
82082	Laramie County, WY 70.7% Banner County 16.8% Kimball County 10.7% Weld County, CO 1.8%	29.3%	4

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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