How no-matches & apartment geocodes improve location data

May 17, 2022

How are no-matches handled?

First things first—what do we mean by “no-match?” A no-match is the result when a geocoding service can’t find a match for the address you entered. There are dozens of reasons this could happen, including typos, missing components, address changes and more. In the result of a no-match, ideally the geocoder would return a response indicating that no matches were found.

Knowing how no-matches are handled tells you how reliable the output data really is. Because unfortunately, not all geocoders operate according to the ideal. Sometimes, instead of telling you there wasn't a match, a geocoder will return a false positive instead.

A false positive geocode occurs when the address is marked as successfully found, but the provided geocode matches the wrong location. Behind the scenes, false positives are what happen when geocoders make guesses on no-match addresses.

False positives are one of the most dangerous forms of bad data because they indicate success despite actual failure.

No-matches vs. false positives: Why does it matter?

Imagine batch processing a million addresses and then being informed your results include between 2,000 and 5,000 geocodes that match wrong locations between 1 block and 500 miles away.

How long do you think it would take you to find all the false positives, if you even could with 100% assurance?

For most businesses, getting a no-match response back is more beneficial than a false positive. If you know an address is a no-match, you then have a chance to flag it for manual review rather than of acting on inaccurate data.

Key questions to ask about geocoding no-matches

Will the geocoder provide explicit “no-match” responses?
Does the geocoder give false positives without a confidence score?

Are apartment or other sub-address geocodes offered?

We’re about to drop some exciting knowledge…

Some geocoding APIs can get even more granular than rooftop accuracy!

Why would you need to go beyond rooftop accuracy? Well, a single rooftop or parcel doesn't always equal a single address. For example, apartment buildings, strip malls, business parks, and other locations may contain many sub-addresses.

If you want to maximize the usefulness of your geocoding provider, find out if the API can accurately identify individual units under a rooftop like strip malls and apartment complexes.

Just remember that if the service isn’t truly “rooftop accurate”—and not all of them are, they’re definitely not going to be able to return sub-address geocodes.

Why do sub-address geocodes matter?

As the saying goes, “Location, location, location!” For example, where a particular condo in a larger complex sits relative to a noisy highway, a popular beach, or a likely-to-flood river, makes a huge difference for risk assessment.

Sub-address geocodes provide more granular insight. In addition, you’ll be able to provide even more detailed data to decision makers.