I am trying to build an application that has a map feature where a user can drill down from state to county to zip code on a map, and do some work from there. To get to this, I found out that some zip codes breach multiple counties. A screenshot is provided below.

I have the county shapefile and the zipcode shapefile from Tiger (Census). What I decided I wanted to do, is split the zip code polygons that breach multiple counties and add the county name to all zip codes (and the new zip code fragments)

I'm working with QGIS to perform the split and cut. I attempted the "CLIP" feature as well as the "clip vector by mask layer" and both resulted in a new layer which did NOT split the zip code polygon.

I'm trying to figure out what I'm missing here.

enter image description here

As you can see, the selected zip code is breaching four counties. I need that zip code split amongst the four counties, so if the user in the application selects a county, then that portion of the zip gets highlighted.

My alternate idea is to duplicate the zip code three times to have one in each county. If that's easier, how can I do that instead.

  • 3
    Sounds like a simple intersection is what you need?
    – 15Step
    Apr 27, 2023 at 10:45
  • Yup. That seemed to work. couldn't tell the difference. Thank you!!! Can you please set that as an answer so I can give you points?
    – arcee123
    Apr 27, 2023 at 10:53

1 Answer 1


So to do that all you need is an intersection, since that will extract the features from the overlay layer, as explained in the documentation:


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