Technically, yes. And it's happened before, will happen again, and is currently happening all the time. In the U.S., we had postal zones in certain cities. A

Technically, yes. And it's happened before, will happen again, and is currently happening all the time. In the U.S., we had postal zones in certain cities. A two digit code to specify where in a large city, the letter was to be delivered. The modern zip code wasn't widely implemented until 1967. And depending on how an area grows, it's possible for a postal zone to get subdivided changing the zip code for certain areas. Also, in 1983, Zip+4 was introduced. So, exactly what you have described has happened. Same thing with area codes for telephones.