Residential delivery index (RDI™)
The Postal Service™ RDI database
allows ZP4 to determine if an address is a residence or a business.
RDI is included on the ZP4 DVD-ROM.
for residence vs. business detection
RDI output can be generated using ZP4's "BDI" and "RDI" output fields.
RDI processing may not be performed after the 30-day expiration date of the RDI database.
Once an RDI database expires, you must purchase a current ZP4 edition to continue performing RDI lookups.
Go to the ZP4 home page.
Semaphore Corporation is a non-exclusive licensee of the
United States Postal Service®.
The prices of Semaphore Corporation products
are not established, controlled or approved by the Postal Service.
The following trademarks are owned by the United States Postal Service:
and United States Postal Service. [DA#4.07]