Does USPS require a return address?
On many kinds of mail, yes. Per pe.usps.com DMM 602.1.5.3, checked 2026-07-27, a sender's domestic return address must appear legibly on Priority Mail, Priority Mail Express, Registered Mail, insured mail and more than a dozen other categories. Parcel labels bought online fall squarely in that world.
Can the from address be a PO Box instead of my home?
Enter whichever real address should receive the package if delivery fails; for many shippers that is a box or a business location rather than a residence. The requirement is that the address works, not that it reveals where you sleep.
What happens to a package that cannot be delivered?
The carrier tries to send it back to the sender address on the label. A parcel with no usable sender line has nowhere to bounce, which is a big part of why the rules and the label formats insist on one.
What does a flat mailer cost to send?
Our 2026-07-27 quote for a roughly 13 x 9 in flat under half a pound, Newark to Atlanta, started at $8.38 with USPS Ground Advantage, with faster tiers topping out at $15.38 for UPS 2nd Day Air.