FAQs#
General#
How frequently do Zip Codes change?#
Every year, the United States Postal Service makes thousands of changes to Zip Code records. Cities may be added and removed and Zip Codes may be created or discontinued. We receive monthly updates to our zip code data so our Zip to District files are as accurate as possible.
What is the difference between population-based and centroid-based matching?#
Most zip to district services match a zip code area to a legislative district based on the center or “centroid” of that area. Since zip codes can cut through legislative districts, this may not always be the most accurate. In addition to centroid matching, we offer an increased accuracy option that takes population into account.
Pricing#
What is the price of the Zip to District files?#
The price varies based on the data you need. Contact us for a custom quote.