First three digits · Iowa
ZIP Codes Starting with
5 ZIP codes start with 507, sorted at the Waterloo, IA (SCF 506) sectional center (USPS labeling list L005, effective October 1, 2026) in Iowa: 4 residential ZIP codes across 1 county and 1 PO Box or single-organization code (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 507 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 507, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 507 to the Waterloo, IA (SCF 506) facility. The last two digits pick the delivery area. By residents, the largest town names among the 507 ZIP codes are Waterloo and Evansdale.
The same facility sorts 4 prefixes, 165 ZIP codes in all: 504, 506, 507, 521.
Where are the 507 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 507
| County | ||||||
|---|---|---|---|---|---|---|
| 50701 | Waterloo | Black Hawk County | 30,232 | 382 | $62k | $184k |
| 50702 | Waterloo | Black Hawk County | 20,882 | 2,136 | $62k | $151k |
| 50703 | Waterloo | Black Hawk County | 17,952 | 193 | $50k | $96k |
| 50704 | Waterloo | Black Hawk County | PO Box or unique | – | – | – |
| 50707 | Evansdale | Black Hawk County | 7,784 | 948 | $63k | $154k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.