ZIP+4 Code Format Guide: How to Use 9-Digit ZIP Codes
ZIP+4 codes provide more precise addressing for faster mail delivery. Learn how to format, find, and use 9-digit ZIP codes effectively.
What is a ZIP+4 Code?
A ZIP+4 code is a 9-digit postal code that extends the standard 5-digit ZIP code with 4 additional digits. These extra digits help the USPS identify specific delivery routes, buildings, or groups of addresses within a ZIP code area.
ZIP+4 Format
5-digit ZIP code + hyphen + 4-digit extension
Benefits of Using ZIP+4 Codes
✅ Faster Delivery
- • More efficient sorting
- • Reduced processing time
- • Direct route identification
- • Faster automated handling
🎯 Better Accuracy
- • Precise address identification
- • Reduced delivery errors
- • Better tracking capabilities
- • Improved delivery confirmation
How to Find ZIP+4 Codes
🔍 USPS ZIP Code Lookup
Use the official USPS ZIP Code Lookup tool at tools.usps.com/zip-code-lookup.htm
- • Enter complete street address
- • Provides full ZIP+4 code
- • Validates address format
- • Free official tool
📮 Check Existing Mail
Look at mail you've received at your address for the ZIP+4 code
- • Bills and statements often include ZIP+4
- • Government correspondence
- • Business mail typically uses full codes
- • Bank and credit card statements
Proper ZIP+4 Formatting Rules
✅ Correct Format
- • Always include the hyphen
- • No spaces around hyphen
- • Use all 9 digits
❌ Incorrect Format
- • Missing hyphen separator
- • Hard to read and process
- • May cause delays
When to Use ZIP+4 Codes
📦 Business Mail
Essential for bulk mailings, business correspondence, and certified mail to ensure accurate delivery and tracking.
🏢 Commercial Addresses
Office buildings, apartment complexes, and business districts often require ZIP+4 codes for proper delivery to specific units or floors.
⚡ Time-Sensitive Mail
Important documents, legal notices, and urgent correspondence benefit from the faster processing that ZIP+4 codes provide.
ZIP+4 vs Regular ZIP Codes
| Feature | 5-Digit ZIP | ZIP+4 |
|---|---|---|
| Precision | General area | Specific delivery route |
| Processing Speed | Standard | Faster automated sorting |
| Required? | Yes | Optional but recommended |
| Best For | Personal mail | Business & important mail |
Need Help with Addressing?
Let us handle the addressing, printing, and mailing for you. We automatically use ZIP+4 codes when available.
Send Mail Online →Frequently Asked Questions
What is a ZIP+4 code?
A ZIP+4 code is a 9-digit postal code format that includes the standard 5-digit ZIP code plus 4 additional digits that identify a specific delivery route, building, or group of addresses for more precise mail delivery.
How do I format a ZIP+4 code?
Format ZIP+4 codes as: 5-digit ZIP, hyphen, 4-digit extension (example: 12345-6789). The hyphen is required when writing the full 9-digit code.
Is ZIP+4 required for mail delivery?
ZIP+4 codes are not required, but they are highly recommended for faster processing and more accurate delivery, especially for business mail and important documents.
Where can I find my ZIP+4 code?
Use the official USPS ZIP Code Lookup tool online, check mail you've received at your address, or ask your local post office for your complete ZIP+4 code.