The Plus4.txt file dated 4/28/2008 contains 385 zip/county combinations that do not exist in the ZIPsales Database. As a result, if you are using this Plus4.txt, certain zip+4's will return the DynamicZip Schedule Selection Message “No valid ID found for (city, state zip) in county (county name)”.

Case in point for the above issue of the ZIPsales Database is zip 70380-4400 to 70380-4484. The Plus4.txt file indicates that this zip is located in St Martin county. However, the Zip.txt file contains no record with a zip of 70380 and a county of St Martin.

Known Zipsales Database Issues