US Post Office (USPS) Operating Hours: Holiday Schedules and Sunday Services Explained

The Workaround: Self-Service Kiosks (APCs)

If you missed the counter hours, you do not always have to wait until the next morning. Many main post offices feature a 24/7 accessible lobby equipped with an Automated Postal Center (APC). These self-service kiosks allow you to:

• Weigh packages and print exact postage stickers using debit or credit cards.

• Purchase standard stamps and certified mail services.

• Drop prepaid or freshly stamped packages directly into the secure lobby collection bin.

Pro-Tip: Bins inside 24/7 lobbies have physical size limits. If your package is larger than a standard shoebox, it will not fit through the drop slot and must wait for counter staff during regular hours.

What Really Happens on Sundays? (Sunday Delivery Rules)

A common misconception is that USPS completely shuts down on Sundays. While you cannot walk up to a clerk to buy a box or mail a letter, logistics operations run around the clock.

1. Priority Mail Express Deliveries

Priority Mail Express is the postal service’s flagship overnight option. USPS delivers Express parcels 365 days a year—including Sundays and major holidays—for an added Sunday premium fee. If a sender pays for overnight Sunday delivery, a carrier will physically deliver it to your doorstep.

2. E-Commerce & Sunday Parcel Delivery

Through strategic logistics contracts with major retailers like Amazon, USPS regularly runs Sunday parcel routes in major metropolitan areas and surrounding suburbs. Carriers focus strictly on high-volume parcel drop-offs rather than standard letter mail, ensuring regional sorting facilities stay clear ahead of Monday morning.

3. Collection Mailboxes

The blue mailboxes sitting outside postal facilities or on city street corners are accessible 24/7. However, dropping a letter in a box on Sunday afternoon does not mean it travels that evening. The posted collection times clearly show that Sunday deposits sit securely until the first scheduled truck run on Monday morning.

Federal Holiday Closures: The Complete Calendar

USPS observes all 11 official U.S. Federal Holidays. On these specific dates, retail windows lock, street carriers do not run normal residential routes, and regular mail collection pauses.

When a fixed-date holiday (like July 4th or Christmas) falls on a Sunday, USPS observes the holiday on the following Monday. If it falls on a Saturday, retail services usually observe it on the preceding Friday, though regular Saturday parcel operations may still run in select hubs.