Starting December 24, 2025, USPS officially clarified how postmark dates work. This sounds boring at first, but it actually explains a problem many sellers already see every day: orders dropped off on time, but marked by marketplaces as shipped late.
What changed (or rather: what USPS finally clarified)
Before, most people assumed this:
You drop a package or letter at USPS → that date is the “official” date.
Now USPS clearly says:
The postmark date is the date when the package is first processed by an automated USPS sorting machine, not the moment you dropped it off.
That processing can happen later the same day or even the next day.
This is basically the same logic marketplaces use.
Why this matters for sellers
Marketplaces don’t care when you created the label or when you dropped the package in a bin. They care about when USPS officially scanned or processed it.
So what happens?
- You drop off an order in a USPS box or leave it for pickup
- USPS picks it up, but processes it later
- The first scan happens the next day
- Marketplace sees “received by carrier” one day late
- Order is marked as shipped late (a bummer)
Sound familiar? That’s exactly what this USPS clarification explains.
Simple example
- You drop a package at 6 PM.
- USPS processes it the next morning.
- USPS system date = next day
- Marketplace carrier acceptance = next day
Even though you did everything “on time”, the system says otherwise.
How to avoid late shipment flags
If timing matters, you need proof of carrier acceptance on the same day.
Best options:
- Hand the package to a USPS clerk and get an acceptance scan
- Buy postage at the counter so it’s accepted immediately
- Use services that generate a receipt or acceptance record (Certified, Registered, etc.)
- Avoid relying only on blue collection boxes for cutoff-sensitive orders
Bottom line for sellers
This USPS change doesn’t really introduce a new problem.
It just confirms how things already work behind the scenes.
If your orders are sometimes marked as late even though you shipped them on time, this is why.
Marketplaces trust carrier scans, not intentions.
