US United States Major Regions Postal Code Details
🏛️ Sierra · California
95910
Alleghany
96125
Bassetts
96124
Calpine
95936
Downieville
95910
Forest City
95944
Goodyears Bar
96118
Loyalton
96124
Sattley
96125
Sierra City
96126
Sierraville
📮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).