You've got a package sitting on the counter. It's gotta go out. Maybe it's a birthday gift that's already late, or a return for that sweater that looked way better online than it does on you. You're staring at the clock, wondering: what time does post office open tomorrow? Well, tomorrow is Sunday, January 18, 2026. If you’re looking for a standard retail window where a friendly (or slightly caffeinated) person in a blue uniform takes your box, you're mostly out of luck. Most United States Postal Service (USPS) retail locations are closed tight on Sundays.
But it’s not just a "Sunday thing" this time around. We are currently staring down a long holiday weekend. Since Monday, January 19, is Martin Luther King Jr. Day, the postal schedule is even wonkier than usual.
Sunday Realities and the Monday Holiday
Honestly, it’s a bit of a bummer when you have a deadline. Standard USPS post offices don't open their retail counters on Sunday, January 18. They just don't. You won't find a clerk to help you with certified mail or to sell you a book of stamps.
However, the "lights out" rule isn't 100% universal. If you live in a massive metropolitan hub—think New York, Chicago, or Los Angeles—there are a tiny handful of "Main" post offices that occasionally have limited Sunday retail hours. But for 99% of us? The doors are locked.
The "Self-Service" Loophole
Here is the thing most people forget. Even when the counter is closed, the lobby often isn't. Many post offices keep their lobbies open 24/7 so people can get to their P.O. Boxes.
If your local branch has a Self-Service Kiosk (APC), you’re in business. You can weigh your package, print a shipping label, and drop it in the bin right there. It’s basically a giant ATM for mail. You don't need a human to open the building to get that package into the system.
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Does Anyone Actually Deliver Tomorrow?
You might see a mail truck tomorrow. Don't let it fool you.
While the retail side is closed, the USPS "back-end" is still humming. They have a specific deal with Amazon and other major retailers to deliver packages on Sundays. Also, if you paid for Priority Mail Express, that specifically includes Sunday and holiday delivery.
So, while the post office isn't "open" for you to walk in and ship something easily, the mail is still moving behind the scenes.
The Monday MLK Day Shutdown
Since tomorrow is Sunday, you might think, "Okay, I'll just go Monday morning."
Slow down. Monday, January 19, 2026, is a federal holiday. The USPS observes all 11 federal holidays, and MLK Day is a big one.
- Retail Windows: Closed.
- Regular Mail Delivery: Suspended.
- P.O. Box Access: Usually open, but check your local lobby.
- Priority Mail Express: This is the only thing that keeps moving.
Basically, if you miss the window today (Saturday), your next chance to talk to a human at the post office is Tuesday, January 20, 2026. On Tuesday, most locations will resume their standard 8:00 AM or 9:00 AM opening times.
Better Alternatives for the Impatient
If you absolutely cannot wait until Tuesday, you have to look outside the federal system.
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Private carriers like UPS and FedEx operate differently. While some UPS Store locations are closed on Sundays, many FedEx Office (the old Kinko’s) locations are open seven days a week.
Wait. Check the holiday though. For MLK Day 2026, FedEx usually runs "modified" service. Their retail stores stay open, even if their trucks aren't doing the standard residential routes. UPS, on the other hand, typically shuts down most operations on the actual holiday Monday, though they often keep their "Express Critical" service moving.
Pro-Tip for Sunday Shipping
Go to a grocery store or a pharmacy. Places like Walgreens or CVS often serve as FedEx drop-off points. Some grocery stores have a "postal center" that sells stamps and takes outgoing mail, though they can’t always handle heavy packages or specialized services like Registered Mail.
What You Should Do Right Now
Stop waiting for Tuesday.
If your package is small and you have a printer at home, use Click-N-Ship on the USPS website. You can pay for the postage, print the label, and then just find a blue collection box. If it fits, it ships. Those boxes are accessible 24/7. Just remember that the "collection time" won't happen until Tuesday morning.
If it's too big for the blue box, head to the post office lobby tonight or tomorrow morning to see if they have that kiosk. It'll save you a lot of standing in line once Tuesday rolls around and everyone else who waited is crammed into the lobby.
Check the USPS Locator tool before you drive anywhere. It’ll tell you specifically if your local branch has a kiosk and if the lobby stays open even when the retail counter is dark.
Actionable Next Steps:
- Check for a Kiosk: Use the USPS website to see if your nearest branch has a Self-Service Kiosk.
- Print at Home: Use a service like Pirate Ship or USPS Click-N-Ship to avoid the retail counter entirely.
- Wait for Tuesday: Mark Tuesday, January 20, on your calendar as the official "back to normal" day for all postal services.