The exact words: " Look Up a ZIP Code™ " appear at the top of one of the pages at USPS.com. "Zip Code" seems to have the Trademark™ next to it in many other places on the site, but not everywhere.

According to Wikipedia, it did have some sort of trademark, but it expired.

What sort of trademark was this (without getting too complicated)? And if Wikipedia's right that it expired, can they still use it like a Trademarked Phrase™?

  • 2
    I'll let someone more experienced answer, but "TM" is used for unregistered trademarks; circle-R is reserved for registered marks. A business can use "TM" to claim something is a mark that uniquely identifies their brand without registering it and possibly get some protection under the law, if a court agrees. I do not know the specifics of servicemarks, though, which seem to have slightly different rules (but possibly not substantially different in this particular regard).
    – apsillers
    Commented Apr 26, 2016 at 19:42

1 Answer 1


ZIP and ZIP+4 are registered trademarks.

ZIP Code is a common law trademark or the USPS has an application pending.

Source: Subset of USPS trademarks in Postal Explorer

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