Castro Valley, CA ZIP Codes & Directory
Castro Valley is located in Alameda County in California. Browse all active 5-digit USPS ZIP codes serving Castro Valley and surrounding Alameda County delivery districts.
All ZIP Codes in Castro Valley, CA
2 CodesAbout Castro Valley Mail Delivery & Postal Administration
ZIP codes in Castro Valley are administered by the United States Postal Service. Delivery routes are coordinated through regional Sectional Center Facilities (SCFs) servicing Alameda County and surrounding California metropolitan districts.
Frequently Asked Questions About Castro Valley, CA ZIP Codes
How many ZIP codes serve Castro Valley, California? ▾
Castro Valley, California is served by 2 active USPS postal delivery codes: 94546, 94552.
What county is Castro Valley located in? ▾
Castro Valley is an incorporated city located within Alameda County, California.
What is the population and demographic size of Castro Valley? ▾
According to official U.S. Census Bureau data, Castro Valley has an estimated population of 61,408 residents and is situated within the undefined.
How does mail sorting and delivery work in Castro Valley? ▾
Mail delivery in Castro Valley is operated by the United States Postal Service (USPS) through regional Sectional Center Facility (SCF) distribution plants servicing Alameda County and surrounding California counties.
How much does it cost to ship a package to Castro Valley, CA? ▾
Shipping costs to Castro Valley depend on the package weight, dimensions, shipping carrier (USPS, UPS, FedEx), and the distance from the origin ZIP code. To calculate exact postage rates, use our shipping cost estimator tool.
What is the standard delivery time for mail to Castro Valley? ▾
Standard USPS Ground Advantage typically takes 2-5 business days to reach Castro Valley, depending on the origin. Priority Mail generally arrives in 1-3 business days. Please check tracking for specific regional routing times.