Waterloo, IA ZIP Codes, Area Codes and Address Format

City guides  |  April 10, 2026  |  2 min read

Looking up ZIP codes or writing an address in Waterloo, Iowa? Below is a practical reference built from postal data for the city.

State

Iowa (IA)

County

Black Hawk County

Standard ZIP codes

3

Time zone

Central

Waterloo ZIP codes

These are the standard delivery ZIP codes for Waterloo. The city has 4 ZIP codes in total when PO Box and unique codes are included.

• 50701
• 50702
• 50703

Area codes in Waterloo

Waterloo phone numbers use 319. A single area code keeps local numbers easy to recognize.

Sample Waterloo addresses

The street lines are invented; the city, state and ZIP codes are real. Use them for form testing, mockups and training materials, never for real orders.

How to write an address in Waterloo

• End the address with WATERLOO, IA and the five-digit ZIP code.
• Put apartment or suite numbers at the end of the street line.
• Use USPS abbreviations such as ST, AVE and BLVD.
• Match the ZIP code to the street. Waterloo has 3 codes, so the city name alone is not enough.

More Iowa cities

Iowa City, West Des Moines, Sioux City, Boone, Ackley, or see all Iowa cities.