First three digits · Wisconsin
ZIP Codes Starting with
25 ZIP codes start with 540, sorted at the St Paul, MN (SCF 550) sectional center (USPS labeling list L005, effective October 1, 2026) in Wisconsin: 24 residential ZIP codes across 4 counties and 1 PO Box or single-organization code (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 540 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 540, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 540 to the St Paul, MN (SCF 550) facility. The last two digits pick the delivery area. By residents, the largest town names among the 540 ZIP codes are Hudson, River Falls, New Richmond, Amery, Osceola and Somerset.
The same facility sorts 6 prefixes, 328 ZIP codes in all: 540, 546, 550, 551, 559, 566.
Where are the 540 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 540
| County | ||||||
|---|---|---|---|---|---|---|
| 54001 | Amery | Polk County | 7,906 | 67 | $80k | $287k |
| 54002 | Baldwin | St. Croix County | 6,872 | 88 | $88k | $309k |
| 54003 | Beldenville | Pierce County | 1,065 | 34 | $94k | $344k |
| 54004 | Clayton | Barron County | 2,192 | 28 | $68k | $241k |
| 54005 | Clear Lake | Polk County | 3,264 | 39 | $88k | $274k |
| 54006 | Cushing | Polk County | 852 | 31 | $70k | $204k |
| 54007 | Deer Park | St. Croix County | 1,175 | 26 | $85k | $309k |
| 54009 | Dresser | Polk County | 2,739 | 82 | $90k | $249k |
| 54010 | East Ellsworth | Pierce County | PO Box or unique | – | – | – |
| 54011 | Ellsworth | Pierce County | 7,054 | 68 | $103k | $306k |
| 54013 | Glenwood City | St. Croix County | 3,443 | 33 | $88k | $308k |
| 54014 | Hager City | Pierce County | 2,026 | 48 | $102k | $303k |
| 54015 | Hammond | St. Croix County | 4,086 | 117 | $114k | $327k |
| 54016 | Hudson | St. Croix County | 33,398 | 498 | $113k | $452k |
| 54017 | New Richmond | St. Croix County | 20,366 | 146 | $99k | $322k |
| 54020 | Osceola | Polk County | 7,687 | 104 | $75k | $307k |
| 54021 | Prescott | Pierce County | 7,346 | 168 | $97k | $365k |
| 54022 | River Falls | Pierce County | 24,789 | 180 | $97k | $373k |
| 54023 | Roberts | St. Croix County | 4,620 | 103 | $109k | $385k |
| 54024 | Saint Croix Falls | Polk County | 5,035 | 60 | $75k | $272k |
| 54025 | Somerset | St. Croix County | 7,612 | 152 | $87k | $387k |
| 54026 | Star Prairie | Polk County | 2,361 | 85 | $96k | $342k |
| 54027 | Wilson | St. Croix County | 1,154 | 36 | $101k | $326k |
| 54028 | Woodville | St. Croix County | 2,574 | 69 | $85k | $269k |
| 54082 | Houlton | St. Croix County | 2,190 | 177 | $131k | $476k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.