US United States Major Regions Postal Code Details
📋 United States Address and Delivery Guidance
Include the recipient name, building or street address, locality, region where applicable, postal code when the destination uses one, and the destination country or territory.
Use the language, character set and address order requested by the recipient, official postal operator or carrier. Do not assume every destination uses the same postal-code format.
Confirm the postal code, service coverage and any customs or carrier requirements with the recipient and the relevant official postal operator before shipping.
Postal codes help routing only in territories that use them. Accurate recipient details remain essential for delivery in every destination.
Postal information, sources and verification
Use this page as a routing reference and confirm the complete address, postal code format and delivery restrictions with the relevant official postal operator or carrier before dispatch.
Editorial and service accountability
This postal-code reference is maintained by the 56ok.com logistics-content team for international shipping preparation. It is reviewed against publicly available postal-operator information; it is not an official postal authority and does not replace carrier or customs instructions.
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Your search terms are handled under our Privacy Policy. Review our Terms of Service and disclaimer before relying on any logistics or delivery information.
📮United States Postal FAQ and delivery guidance
📮 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).