Is the term &quot;ZIP Code&quot; trademarked?
<p>The exact words: " Look Up a ZIP Code™ " appear at the top of one of the pages at <a href="https://tools.usps.com/go/ZipLookupAction_input" rel="noreferrer">USPS.com</a>. "Zip Code" seems to have the Trademark™ next to it in many other places on the site, but not everywhere.</p>

<p>According to <a href="https://en.wikipedia.org/wiki/ZIP_code" rel="noreferrer">Wikipedia</a>, it did have some sort of trademark, but it expired.</p>

<p>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™?</p>

<p>ZIP and ZIP+4 are registered trademarks. </p>

<p>ZIP Code is a common law trademark or the USPS has an application pending.</p>

<p>Source: <a href="http://pe.usps.com/text/imm/immc1_006.htm" rel="noreferrer">Subset of USPS trademarks in Postal Explorer</a></p>

trademark legal-history