First three digits · Iowa
ZIP Codes Starting with
20 ZIP codes start with 512, sorted at the Sioux Falls, SD (SCF 570) sectional center (USPS labeling list L005, effective October 1, 2026) in Iowa: 20 residential ZIP codes across 4 counties (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 512 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 512, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 512 to the Sioux Falls, SD (SCF 570) facility. The last two digits pick the delivery area. By residents, the largest town names among the 512 ZIP codes are Sioux Center, Sheldon, Rock Valley, Rock Rapids, Sibley and Hull.
The same facility sorts 6 prefixes, 191 ZIP codes in all: 510, 511, 512, 513, 570, 571.
Where are the 512 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 512
| County | ||||||
|---|---|---|---|---|---|---|
| 51201 | Sheldon | Sioux County | 6,430 | 56 | $69k | $198k |
| 51230 | Alvord | Lyon County | 478 | 20 | $76k | $191k |
| 51231 | Archer | O'Brien County | 562 | 23 | $108k | $190k |
| 51232 | Ashton | Osceola County | 658 | 11 | $83k | $108k |
| 51234 | Boyden | Sioux County | 1,172 | 24 | $84k | $212k |
| 51235 | Doon | Lyon County | 1,007 | 19 | $71k | $241k |
| 51237 | George | Lyon County | 1,605 | 17 | $62k | $160k |
| 51238 | Hospers | Sioux County | 1,502 | 31 | $74k | $183k |
| 51239 | Hull | Sioux County | 2,876 | 43 | $78k | $237k |
| 51240 | Inwood | Lyon County | 1,914 | 19 | $84k | $233k |
| 51241 | Larchwood | Lyon County | 2,103 | 23 | $87k | $281k |
| 51242 | Lester | Lyon County | 379 | 70 | $96k | $191k |
| 51243 | Little Rock | Lyon County | 735 | 14 | $84k | $92k |
| 51244 | Matlock | Sioux County | 144 | 381 | $83k | $95k |
| 51245 | Primghar | O'Brien County | 1,377 | 18 | $70k | $150k |
| 51246 | Rock Rapids | Lyon County | 4,041 | 25 | $72k | $248k |
| 51247 | Rock Valley | Sioux County | 5,094 | 45 | $78k | $263k |
| 51248 | Sanborn | O'Brien County | 1,534 | 19 | $64k | $173k |
| 51249 | Sibley | Osceola County | 3,564 | 28 | $62k | $161k |
| 51250 | Sioux Center | Sioux County | 9,970 | 136 | $94k | $294k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.