How to Find a ZIP+4 Code for an Address?

A ZIP+4 code is an extension of the basic five-digit U.S. ZIP code. It contains the standard five-digit ZIP code, followed by a hyphen and four additional digits.

For example:

12345-6789

To find the ZIP+4 code for a particular U.S. mailing address, use the official USPS ZIP Code Lookup and enter the complete address.

Do not try to guess the additional four digits.

What Is a ZIP+4 Code?

A standard ZIP code contains five digits.

For example:

12345

A ZIP+4 code contains nine numerical digits and is normally written with a hyphen:

12345-6789

The code consists of:

• 12345 – The basic five-digit ZIP code

• 6789 – Four additional digits that provide more specific postal information

ZIP+4 gives USPS more detailed routing information within a five-digit ZIP code area.

How to Find a ZIP+4 Code

Follow these simple steps:

1. Go to the official USPS ZIP Code Lookup.

2. Select By Address.

3. Enter the house or building number.

4. Enter the street name.

5. Add the apartment, suite, or unit number when applicable.

6. Enter the city.

7. Select the state.

8. Click Find.

9. Compare the returned address with the address you entered.

10. Check the ZIP+4 code shown for the matching address.

Always make sure the returned street and unit information matches the destination you actually need.

What Information Do You Need?

To search for a ZIP+4 code using an address, have the following information ready:

• House or building number

• Street name

• Apartment number, if applicable

• Suite or unit number, if applicable

• City

• State

Providing complete address information can help you identify the appropriate result.

Why Should You Use the Complete Address?

A five-digit ZIP code represents a postal delivery area, not one individual address.

The same five-digit ZIP code may cover many:

• Houses

• Apartments

• Businesses

• Offices

• Buildings

• Streets

Therefore, knowing only the basic five-digit ZIP code is generally not enough to determine the ZIP+4 for a particular address.

For a specific destination, use the complete mailing address when performing the lookup.

Can I Find a ZIP+4 Using Only a ZIP Code?

A five-digit ZIP code alone does not normally identify the ZIP+4 for one specific address.

For example, knowing:

12345

does not automatically tell you that the extended code is:

12345-6789

The final four digits should not be invented, guessed, or calculated from the five-digit ZIP code.

Instead:

• Enter the complete mailing address.

• Check the matching address result.

• Use the ZIP+4 shown for that address.

What If You Cannot Find the ZIP+4?

If you do not receive the expected result, check the address carefully.

Look for:

• Incorrect house or building number

• Misspelled street name

• Incorrect city

• Incorrect state

• Missing apartment number

• Missing suite number

• Missing unit information

If someone else provided the address, ask them to confirm their current mailing information.

Do not randomly change parts of an address simply to produce a result. Make sure the result actually matches the destination you need.

ZIP Code vs. ZIP+4

The main difference is the level of postal detail.

ZIP Code

Example: 12345

• Contains five digits

• Identifies a postal delivery area

• Provides basic postal routing information

ZIP+4

Example: 12345-6789

• Contains the five-digit ZIP code plus four additional digits

• Provides more specific postal information

• Helps identify a more precise delivery segment within the ZIP code area

Both are part of the U.S. postal addressing system.

Frequently Asked Questions

Is ZIP+4 the Same as a 9-Digit ZIP Code?

Yes. A ZIP+4 contains nine numerical digits in total. It is normally written as five digits, followed by a hyphen and four additional digits.

Example:

12345-6789

Can I Guess the Last Four Digits?

No. Do not guess the final four digits.

Use an address-based USPS lookup to find the ZIP+4 associated with the matching mailing address.

Are ZIP+4 Codes Used for Apartment Addresses?

When looking up an apartment address, include the apartment or unit information when applicable.

Enter:

• Building number

• Street name

• Apartment or unit number

• City

• State

Then check the ZIP+4 returned for the matching address.

How Can I Find My ZIP+4?

Use the official USPS ZIP Code Lookup with your complete mailing address.

Enter the street address, city, state, and apartment or suite information when applicable. Then check the ZIP+4 displayed for the matching address.

Key Points to Remember

• A ZIP+4 contains the basic five-digit ZIP code plus four additional digits.

• A ZIP+4 is commonly called a nine-digit ZIP code.

• Use your complete address when searching for ZIP+4.

• Include apartment, suite, or unit information when applicable.

• Check that the returned address matches your intended destination.

• Do not guess or calculate the final four digits.

• Use the official USPS ZIP Code Lookup for address-specific ZIP+4 information.

Final Answer

To find a ZIP+4 code for an address, enter the complete street address, city, state, and apartment or suite information, when applicable, into the official USPS ZIP Code Lookup.

Compare the returned address carefully with your intended destination and use the ZIP+4 shown for the matching address.

Do not guess the four additional digits.