25th Avenue
Post Office — San Mateo, CA
Address & Contact
135 W 25th Ave
San Mateo, CA 94403
Parking: Street Parking Available
Get directions →Hours
- Retail Hours
- Mon-Fri 9:30am - 5:00pm, Sat-Sun Closed
- Lobby Hours
- Mon-Sun 12:01am - 11:59pm
- PO Box Access
- Mon-Sun 12:01am - 11:59pm
- PO Box Delivery
- Mon-Fri 11:00am, Sat-Sun Closed
Show all hours →
- Pickup Services
- Mon-Fri 9:30am - 5:00pm, Sat-Sun Closed
Services
Apply for a PO Box
Compare box sizes and pricing, and see what you need to apply.
Hold Mail Service
Pause mail delivery for up to 30 days, free, while you're away.
Change of Address
File your address change directly with USPS to forward your mail.
Certified Mail
See the cost, and what happens if no one's there to sign.
Missing Mail & Lost Packages
Package says delivered but isn't there? See what to do.
General Delivery
Receive mail here without a fixed address. See how to address it.
Nearby Post Offices
Helpful guides
Money Orders
Money orders are a safe way to send payments through the mail. See current fees and maximum amounts.
Post Office Holiday Schedule
Post offices close for all federal holidays. See this year's full schedule so you can plan ahead.
Post Office Weekend Hours
Weekend hours vary a lot by location. See typical Saturday and Sunday patterns before you visit.
Information last verified July 31, 2026. Always confirm details directly with the office before visiting.