Address content is standardized and validated according to U.S. Postal Service CASS standards, which are documented in USPS Publication 28 USPS Postal Addressing Standards (http://pe.usps.com/cpim/ftp/pubs/pub28/pub28.pdf) and CASS system documentation.
Examples of standardization applied include steps to:
- Correct the city and state if they are discernible
- Correct the ZIP code if needed, based on other address content
- Add the +4 extension to five-digit ZIP codes
- Correct the street name if it is misspelled in simple ways
- Correct the street type if it is incorrect
- Validate the house and/or building number
- Verify the suite, floor, unit, and so on, if it is needed for an address.
Note: Some addresses require the suite number.
- Standardize abbreviations for streets
- Standardize capitalization
- Add directional for streets, if applicable, pre- and post- street name (N, S, E, W, NE, NW, SE, SW)
Reference: You can access a web-based validation tool at https://tools.usps.com/go/ZipLookupAction!input.action.
