Free address look-up tools:
- SmartyStreets: 250 free lookups every month.
- Experian data quality: verify up to 500 addresses for free against the USPS database (no mention if per month or total).
- American Factfinder Address lookup: provided by the U.S. Census Bureau, this tool has been used by LINKcat libraries for years to determine the municipality of a patron's legal place of residence. Provides geographical, municipal and political information about the address you submit.
- USPS provides address verification and change of address (COA) tools, many through vendors that may allow a set number of free searches and require payment after that.
- The Zip+4 Code Lookup tool can be used to confirm street address, City and zip code information.
- Viewing the USPS change-of-address database (NCOA) requires end-user certification and licensing. There are multiple vendors that are certified and licensed to provide this service; the amounts charged vary according to the number of addresses submitted.
- BatchGeo: up to 250 addresses mapped for free each month. Allows you to map out a set of addresses, from Excel format, so you can look at the set and see if any of the addresses you submitted lie outside of the range you are confirming. For example, if you have a set of addresses that are marked as being in the "Town of X", use the BatchGeo mapping software to confirm that all of the addresses lie within that town. If not, use the American FactFinder Address lookup tool to find the correct municipality for an address.
USPS Publication 28 - Postal Addressing Standards
- Appendix B - Two-Letter State and Possession Abbreviations (p. 55)
- Appendix C - Street Abbreviations (p. 59)
- Appendix F - Address Standardization — County, State, Local Highways (p. 79)