US United States Major Regions Postal Code Details
🏛️ Marshall · South Dakota
57421
Amherst
57430
Britton
57232
Eden
57270
Hillhead
57430
Kidder
57247
Lake City
57454
Langford
57430
Newark
57247
Red Iron Lake
57430
Spain
57430
Sunset Colony
57270
Veblen
📮US United States Regional Postal Code FAQ & Postal Regulations
📮 What is the format of a US ZIP code?
Standard format is 5 digits (e.g., 10001). Extended format is ZIP+4 (9 digits like 10001-1234) with a hyphen.
🔍 How to find the ZIP code for an address?
Use the USPS ZIP Code Lookup tool by entering the full address on the official USPS website.
⚠️ What happens if I use a wrong ZIP code?
Mail may be delayed, returned, or lost. For important documents, use USPS tracking and verify the ZIP code.
🔄 Do ZIP codes ever change?
Yes, USPS may update ZIP codes due to regional adjustments. Always confirm your ZIP code after an address change.
📦 Is a ZIP code required for international mail to the US?
Absolutely. Always include the US ZIP code at the end of the address (e.g., New York, NY 10001 USA).