Security Sq Post Office
is currently closedThis USPS post office is located in Windsor Mill, MD where the date and time is currently: 4/1/2026, 5:54:07 PM
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Retail Hours
| Day | Open | Close |
|---|---|---|
| Monday | 11:00 AM | 1:00 PM |
| Tuesday | 11:00 AM | 1:00 PM |
| Wednesday | 11:00 AM | 1:00 PM |
| Thursday | 11:00 AM | 1:00 PM |
| Friday | 11:00 AM | 1:00 PM |
| Saturday | 11:00 AM | 1:00 PM |
| Sunday | Closed | |
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Phone numbers
- Phone:410-594-9284
- Fax: 410-594-9318
Services at Security Sq Post Office
Parking lot available. Here's what you can do at this location:
Shipping
- Label Broker
- For online sellers: give your customers a Label Broker ID or QR code so they can print a prepaid USPS return label at this post office — no printer needed.
- Priority Mail International
- Affordable international shipping with delivery in 6–10 business days to most countries. Includes tracking and insurance up to $200.
Passport
- Passport Photos
- Get a compliant passport photo taken on-site. The photo meets all U.S. Department of State requirements so your application won't be delayed.
Money & Financial
- Domestic Money Orders
- Purchase money orders up to $1,000 each — a secure way to send payments without a bank account. Accepted nearly everywhere and traceable if lost.
- Money Order Inquiries
- If a money order is missing, lost, or stolen, you can file an inquiry here. Bring your receipt — USPS can trace and replace it.
- International Money Orders
- Send money orders to other countries through the USPS international network. Available for select countries with limits that vary by destination.
Other Services
- Customer Service Referrals
- Staff can help answer questions or direct you to the right resource for issues with mail delivery, address changes, or other USPS services.
- Federal Duck Stamps
- Purchase a Migratory Bird Hunting and Conservation Stamp — required for waterfowl hunting in addition to a state license. Proceeds fund wetland conservation.
- Greeting Cards with Postage
- Buy greeting cards that already include postage — write your message, address it, and drop it in the mail. No stamps needed.