U.S. ZIP Codes Database 2026
Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.
ZIP Code Details for Dubuque
Detailed geographic and postal record lookup for the city of Dubuque.
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.
Geographic Map of Dubuque, IA
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.
Geographic Map of Dubuque, IA
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.
Geographic Map of Dubuque, IA
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.
Geographic Map of Dubuque, IA
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.
Geographic Map of Dubuque, IA
Postal Information
About U.S. ZIP Codes
U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.
Geographic Breakdown:
- 1st Digit: Represents a group of states or a broad national region.
- 2nd/3rd Digits: Represent a regional area or large city.
- 4th/5th Digits: Identify specific post offices or delivery zones.
ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.