The Changing of the ZIPs

Mr. Zip
Mr. Zip

ZIP codes change. Longtime blog readers know this. They’re based on mail delivery routes
and post office locations, not on established neighborhood areas. While a neighborhood might stay the same, a local post office can close and change the whole ZIP code makeup of the area.

Our ZIP code boundaries come from a company called Maponics. They update their ZIP code maps constantly, based on information from the U.S. Postal Service.

In order to maintain some order to our maps, we update our ZIP codes once a year. That update has just happened, so if you go to PolicyMap now, you can see the most recent ZIP codes. We’ve noticed quite a number of changes, including to our home ZIP code, 19103.

ZIP code 19103. The red outline is last year's boundary, the gray is this year. Note the changes around the edges.
ZIP code 19103. The red outline is last year’s boundary, the gray is this year. Note the changes around the edges.

So what does this mean to you, besides getting more accurate map boundaries? If you’ve made a custom region out of assembled ZIP codes, it might be important:

  • If the ZIP codes in your custom region changed shapes, your custom region changes shape as well. If you had a custom region with 19103, it will continue to be of 19103, as it exists now.
  • If the ZIP codes in your custom region were removed, then the custom region no longer reflects current ZIP code boundaries, but reflects the boundary as it existed before the update.

And as usual, any time we talk about ZIP codes, it’s mandated by federal law that we embed this 60’s era musical video commissioned by the U.S. Postal Service: