Composite Locator FAQ

What is the MD Composite Locator?


A composite locator consists of two or more individual locators or geocode services. When addresses are geocoded against the composite locator, they are automatically matched against each of the individual locators and services.  The MD Composite Locatoe contains Maryland specific data sources for geocoding.

How do I connect to and use the MD Composite Locator?


Please visit the How to use composite locator document for instructions on connecting and using the locator.

Who contributes to the MD Composite Locator?


The data for the Composite Locator comes from a number of Federal, State and Local sources. They include individual counties and municipalities, Maryland Department of Planning, Maryland State Highway Administration, and the U.S. Geologic Survey. Please visit the Composite Locator Data Sources page view to the full list of datasets and sources.

How accurate is the MD Composite Locator?


​The Composite Locator “cascades” through each participating data set to find the best match of the address you are trying to locate. Our locator contains Address Points, which match a search to a point on top of a building. Address Points are the most accurate data set in the locator.

Do you include locations outside of Maryland?


​No, currently the composite locator only includes locations within Maryland.  The GIO is actively investigating including non-Maryland data sources to the MD Composite Locator.

How often is the MD Composite Locator updated?


The locator is updated at least once in every 3 months with new address, centerline ranges and parcel data.

An address came up in Google Maps / Bing Maps but not the Composite Locator, why?


Google and Bing Maps can interpolate non existent addresses to the closest existing address range, the MD Composite Locator is designed to match only the addresses that are in existence.

How do I report a problem with the Composite Locator?


Please contact the GIO Office at for more information.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

How can I geocode without using a GIS/mapping software?


You can geocode your addresses using the batch geocoder by uploading the addresses in a spreadsheet format.

What is the difference between Single Line and Multi Line geocoding?


The composite locator supports both single line and multi-line geocoding. You can learn more about it here.