Since I did address database software for public libraries for a couple of decades.... Addresses are complicated. In North American (USA & Canada) there are approximately 80,000 localities, counties, states and federal addressing authorities (mostly local building and planning departments). These are the official (legal) addressing authorities. Tax and real estate records usual the legal property definition. Because its a PITA to deal with 80,000 different authorities... The USPS (and Canada Post)) maintains a national directory of addresses valid for mailing purposes. Not every address. The addresses they deliver based on local jurisdiction address information, but modified for postal needs. The telephone company (formerly Ma Bell, then ILECs, now PSAPs and states) maintain the Master Street Address Guide (MSAG) for E911 purposes. Again based on local jurisdication address information, but modified for telco/cellular/PSAP needs. The US Census maintains TIGER and Master Address File (MAF) for planning enumeration operations every 10 years. Geocodes domiciles (i.e. where people live, not work) for census workers, not necessarily postal or telephone addressses. Several commercial (i.e. expensive) databases for various purposes, such as driving, mapping, advertising, etc; all use one of the government address databases as their base. Enhance the base information with satellites, airplane and street view mapping. When a record is wrong, figuring out the source is a bit of an art. Mail/Shipping/Ecommerce => start with USPS database Telco/wireless/E911 => start with MSAG database Politics/Gerrymandering => start with Census database Tax, real estate, other => start with local building/planning department On Thu, 30 May 2024, Mike Hammett wrote:
This is the Internet, after all, so I will be corrected if I'm wrong. 911 is based on MSAG (Master Street Address Guide), not USPS. However, many operators are likely using the USPS system to sanitize the inputs.