How do I find a ZIP code by city or state?

You can find ZIP codes by city or state using our search tool. Just enter the city or state name, and you'll see all related ZIP codes instantly.

What is a ZIP+4 code?

A ZIP+4 code adds four digits to the basic five-digit ZIP code. It helps the USPS deliver mail more precisely to specific addresses or buildings.

Are ZIP codes the same as postal codes?

ZIP codes are the U.S. version of postal codes, used by the USPS to identify delivery areas. Other countries use postal codes with different formats.

All ZIP Codes for Castro Valley California – Postal Code Lookup

Castro Valley ZIP Code

The city of Castro Valley is assigned specific ZIP Code(s) by the United States Postal Service (USPS) to make mail delivery accurate and efficient. A ZIP Code in Castro Valley helps identify the correct postal area, ensuring that letters, parcels, and packages reach the right neighborhood or post office without delay. For residents, businesses, and visitors, knowing the correct Castro Valley ZIP Code is important not only for mailing purposes but also for location-based services, navigation, and demographic reference.

Castro Valley

Post Office	Castro Valley
Division	Alameda
Pincode	94546

Castro Valley

Post Office	Castro Valley
Division	Alameda
Pincode	94552

Total Post Office (2) Page 1 of 1

Zip Codes in Castro Valley, California

Zip Code list in Alameda for your selected city Castro Valley is shown below. Use these ZIP Codes to ensure accurate mail delivery, business operations, or location reference.

94546

94552

About Castro Valley, California ZIP Codes

Castro Valley is located in Alameda County, California. The United States Postal Service (USPS) assigns multiple ZIP Codes in this region to simplify mail distribution, navigation, and address identification. Each ZIP Code in Castro Valley covers a specific neighborhood or area, which is important for residents, businesses, and government offices. Having the correct ZIP Code ensures smooth delivery of letters, online orders, and official documents.

Why Knowing the ZIP Code is Important?

Ensures accurate and timely mail delivery
Helps businesses and eCommerce platforms verify addresses
Useful for demographic research and census data
Required for utilities, banking, and government services

Frequently Asked Questions (FAQs) about Castro Valley ZIP Codes

The primary ZIP Code for Castro Valley, California depends on the specific neighborhood. Use our list above to find the correct code.

Castro Valley has multiple ZIP Codes covering different areas of the city. Check the table above for the complete list.

You can use our ZIP Code lookup tool by selecting the city, county, and state to locate the right code for your address.

All ZIP Codes in Castro Valley are assigned and managed by the United States Postal Service (USPS) for accurate mail sorting and delivery.

Yes, in many cases a single ZIP Code can cover more than one neighborhood or locality in Castro Valley to simplify mail distribution.

ZIP Codes usually remain stable for decades, but USPS may introduce new codes or adjust boundaries when population grows or new delivery routes are added in Castro Valley.