[Talk-us] USPS Address Database

Alan Mintz Alan_Mintz+OSM at Earthlink.Net
Wed Mar 2 23:37:38 GMT 2011

At 2011-03-02 11:23, Brian Wilson wrote:
>You'd be better off trying to get tax assessor data on a county by
>county basis and then create centroids from the parcels. Tax assessors
>are pretty good at keeping their records up to date because they have
>to have accurate data to tax us.

Almost. Unfortunately, the actual mail-delivery addresses, usually assigned 
by cities, are not particularly important to the county assessors. As I 
started to analyze San Bernardino County, CA (the largest county in the 
US), finding many parcel address problems, I queried the assessor about it, 
and received this response:

"...As you have noted, there are considerable errors in the parcel situs 
address information. This is largely due to this data being of secondary 
importance to the Assessor's Office. The address of primary importance is 
the owner address which is critical for mailing purposes. Historically, the 
situs address info. is collected when a parcel becomes occupied and would 
only be updated if the property owner submits an address change request. 
Over the years as zip code and city limit boundary changes occur, they may 
not be reflected in the situs address. With the advent of GIS, the situs 
address has gained greater visibility, usability and importance. Because of 
this, the Assessor's Office is beginning to make corrections to the situs 
address data as they are made aware of problem areas. Overtime, we hope to 
see significant improvements in this information."

So, there is hope. I haven't audited any other county's parcel addresses.

Alan Mintz <Alan_Mintz+OSM at Earthlink.net>

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