Where Did They Move To? has been an experiment in the use of computer and Internet technology to track change-of-address information filed by people who have moved. A few archived pages for the older phases described below can still be viewed using the Internet Archive Wayback Machine.
Phase 1 began in 1996, and featured an online database by which Internet users could file a change-of-address record or retrieve change-of-address information for other people already on file. Access to this database is no longer available.
Phase 2 began in May 1998 when Semaphore Corporation applied to become a licensee of the Postal Service™ FASTforward® change-of-address database, which contains data from the change-of-address cards people fill out at the Post Office™ when they move, so their mail will be automatically forwarded to their new address. Beginning in November 1998, this site provided free FASTforward address lookups. At that time, Americans were filling out about 40 million change-of-address cards each year (averaging more than one per second, every second around the clock). During Phase 2, this site provided 172,754,410 free old-address lookups and returned 3,404,568 new forwarding addresses (the industry standard 2% hit rate). Free lookups using the Postal Service change-of-address database are no longer available at this site. The ZIP + 4® database (which contains only address data, not personal names) remains available.
Phase 3 began in March 1999 with the release of source code allowing a Windows machine connected to FASTforward "black box" hardware to perform change-of-address lookups. The Postal Service licensed FASTforward systems to companies for $5,000 per year, so mailers could convert files of old addresses to new addresses and avoid wasting time and postage sending mail to obsolete addresses. Phase 3 ended when Semaphore Corporation switched from FASTforward to NCOALink® development.
Phase 4 began June 30, 2003, when the Postal Service announced NCOALink, which allows mailers to access the change-of-address database on DVD-ROM without having to acquire FASTforward hardware, and we began changing our FASTforward software into NCOALink software.
Phase 5, during which we offered our certified NCOALink software free to anyone who completed the required Postal Service end user certification and licensing procedures, ended September 21, 2006. Even though our NCOALinksoftware was available at no charge, end users were still required to pay the Postal Service their annual four-figure fees before receiving the DVD-ROM database.
Although about 20% of Americans change their address each year, service bureaus usually can't find forwarding addresses for more than about 2% of your records. Unfortunately, a bureau will require a minimum quantity of addresses, and charge you for processing every record in your list, so converting addresses usually pays off only for very large lists. (Processing 1,000 names will typically only find 20 of the 200 people who actually moved; processing 1,000,000 names will probably find 20,000 of the 200,000 people who moved.)
Therefore, it can be preferable to not pre-process a list before you mail in order to detect movers. Instead, simply send mail using the proper barcode to request ACS™ service, which will return all forwarding address changes to you electronically.
Postal Service databases only contain information people submit about themselves to the Post Office using change-of-address forms. If someone has moved and doesn't want to be found, it's unlikely they submitted their forwarding address to the Postal Service. If someone has moved and does want to be found, sending a postcard with the proper forwarding "endorsement" to their old address is essentially equivalent to attempting a database lookup (consult your Postmaster and/or the Domestic Mail Manual to determine the best endorsement for the proper forwarding or return of your mail piece).