Is it mandatory to put a return address on mail to the US?

While at the post office with a friend today, she said she’d heard that it is now mandatory to put a return address on any mail sent to the US, and that without a return address, the mail could legally be opened/ thrown away/ not delivered.

She seemed to think it was some sort of anti-terrorism measure, but did stress she couldn’t remember where she’d heard it, and had no idea whether or not it was true.

So: is a return address mandatory?

Here’s what the postal manual on the USPS website currently says:

It would seem to me that something like a Christmas card to Aunt Judy would not fall into these categories.

From: Joe Da Terrorist.

Yeah, I see how that would work.

Wait, couldn’t Joe just use Sister Bertrille as his return addressee? Or are they not that cunning?

You said “it is now mandatory to put a return address on any mail sent to the US.”

Note: “to the US” not “within the US.”

Please tell us what country you are sending this mail from. Each country is free to create its own postal regulations.

If I put the destination address where the return address should go and forget to apply postage, will they “return” it to the intended recipient?

If a letter cannot be delivered because the address is incorrect or invalid, and there is no return address on the envelope, postal employees have the right to open and inspect the contents to find clues about where to deliver (or return) the mail.

Sometimes, but they don’t have to. (I will confess, I owe the post office about 60cents from the 1980’s.)

To clarify: the implication was that it was a USPS (or similar) regulation which applied to mail being sent into the US from other countries, rather than legislation which applied in the country the mail originated from.

So without a return address, the USPS/ other American government body would be legally entitled to open or dispose of the item.

It depends. IIRC the USPS will not return to sender if the letter was not mailed from the same town (or perhaps a nearby town) as the return address. i.e., if a letter with a Chicago return address is mailed from Chicago without a stamp, they’ll give the “sender” the benefit of the doubt and return it. However, if the return address was in, say, Miami, they might assume that a Chicago resident is trying to trick them into sending the letter to someone in Miami for free, and they won’t deliver it.

The government is legally entitled to open incoming international mail already. Fourth Amendment applies with considerably less force at international borders.

There was a time when this almost always worked. When I lived in a college dorm about 1952-59 almost all outgoing mail had the destination as the return address and no postage.
At some point in time they caught on and changed the rules.

I just mailed a package at the post office yesterday with no return address. I was asked if I wanted to put one on, but said no because it was a secret Santa gift. Not a problem at all.

And if, like many did, they put their own address as the deliver-to address, the Post Office might just get even by delivering it to that Chicago address, with a 45¢ postage-due note, plus a 25¢ fee. And the letter still didn’t get to Miami!

Depends on what mail service you are using. Registered mail, or any type of correspondence that has to be signed for won’t be accepted without a return address. However, that doesn’t stop anyone from dropping something in the mailbox without a return address. Postcards for example. (Mail without postage will be delivered and the recipient will be charged with postage due, although the PO isn’t as aggressive as much as they once were to collect.)