This article was originally published in the February 2018 Princeton Echo.

The large area outlined in red is 08540; the smaller red area is 08542 and 08544 (Princeton University). The town of Princeton is the area outlined in black.

People love to say they live in Prince­ton. A person I met recently told me, “I live in Princeton, too, in Kingston.” A toddler I once babysat nearly cried when, after insisting that he lived in Princeton, I told him that he actually lived in West Windsor. And in fairness, their mailing addresses did end in Princeton, New Jersey, 08540.

Princetonians, on the other hand, can be quite protective of their town’s true borders. When I moved to my current house — on a road that also runs through Lawrence and Montgomery townships — and went to renew my Princeton Public Library card, a librarian looked at my driver’s license skeptically and asked, “Are you sure you really live in Princeton?” Unless I’m making several thousand dollars in completely voluntary donations to Princeton’s tax collector each year, I’m pretty certain. But that’s not the case for many people who share Princeton’s 08540 zip code.

One recent weekend I logged on to Verizon’s website to check the number for a specific television channel. Its lookup program prompts you to enter your zip code and then asks to verify your location. When I entered 08540 I had my choice of seven towns in addition to Princeton where I might live: Franklin, Hopewell, Lawrence, Montgomery, Plainsboro, South Brunswick, and West Windsor.

So just how far does the 08540 go? What once was Princeton Township and the outskirts of the Borough — excluding the center of town, which maintains its separate 08542 zip code — covers around 17 square miles and had a population of roughly 23,000 in the 2010 census. The 08540 zip code covers 51.92 square miles, including parts of each of the towns listed above, and has a population of more than 47,000.

This is not unique to Princeton. Zip codes, when they were instituted in 1963 were not designed to align with municipal boundaries. And while zip codes can cover more than one town, the postal service designates a “preferred” place name to associate with each zip code. In the case of 08540, the preferred name is “Princeton.”

And it turns out that the toddler in West Windsor is not the only one to have trouble digesting his real home town. The Wikipedia article on zip codes notes: “Postal designations for place names become de facto locations for their addresses, and as a result, it is difficult to convince residents and businesses that they are located in another city or town different from the preferred place name associated with their zip codes.”

Of course, you don’t have to live in the zip code associated with Princeton to borrow its name. Largely because of its eponymous university, the Princeton name carries a level of prestige and name recognition that leads entities far from the town’s borders to borrow the Princeton name. “Princeton South Corporate Center” — in Ewing Township — is more than seven miles by car from Princeton’s closest border. Community News Services’ offices are located roughly three miles from the Princeton township line, in a complex aptly named “Princeton South at Lawrenceville.” Similarly, on Ridge Road in South Brunswick there is an apartment complex called “Princeton Orchards,” located seven miles from the intersection of River Road and Route 27, where Princeton becomes Kingston.

And until last month the nearest hospital was called the University Medical Center of Princeton at Plainsboro — despite being located in Plainsboro and bearing no relation to Princeton University. Now that it has merged with Penn Medicine, it has dropped Plainsboro from its name: it’s now called Penn Medicine Princeton Medical Center.