"You know, I call it the Great Highway. It says that on the sidewalk," says resident Rachelle Levy.
And for decades, residents in the 1500 block have used the Great Highway as their mailing address. But look closely, and the Great Highway merges with La Playa Street.
The post office says that's the name on property deeds, and so it will stop delivering anything labeled otherwise.
"We updated our database about a year ago and the city said La Playa is the legal address for this particular block in the city, so we put that into the system," says James Wigdel of the Postal Service.
But residents we talked to say they were never notified.
Donald Aissa only realized something was wrong when he got a call the other day from his insurance company.
"Saying they got my returned mail from this address, the Great Highway, and they asked if I had a change of address and I said no, not that I know of."
According to the neighbors, there are 94 apartments and six houses on this one block -- all impacted by the change.
"I've been getting a lot of residents coming up to me very hostile. I just deliver the mail," says mail carrier Jhulsang Futol.
The post office says they are still delivering to both addresses, but recently gave one neighbor a 60 day warning that the Great Highway was on its way out. She alerted others on the block that they would soon have to change their checkbooks, their id's and tons of other documents. Now, the district's supervisor is trying to mediate.
"Whether it's talking to the Department of Public Works, the Assessor's Office, talking to the post office, those are things we're prepared to do," says San Francisco Supervisor Carmen Chu.
The post office now says it's willing to give the 1500 block of the Great Highway/La Playa time to adjust, maybe even up to a year.