The ALL_ADR.TXT file is a 7-column, comma-delimited table with the following format:
PCode, Primary/Alternate Location, State, County, Locality, Beginning Zip Code, Ending Zip Code
A frequently asked question concerns the purpose of the Primary/Alternate location flag. The best way to answer that is with an example -
It is set to either '0' or '1' depending on whether the corresponding location is a "Primary" location or an "Alternate" location. As an example, I am sitting in an office in Lenexa, KS. If you mailed me something and it was addressed to Lenexa, KS, you'd be sending it to my primary location. However, because the very first post office to serve this area was set up at the Shawnee Methodist Mission in the early nineteenth century, the whole area (which encompasses nearly a dozen cities - or "primary locations") is also referred to as "Shawnee Mission, KS." Thus, if you sent me mail addressed to Shawnee Mission, KS, you'd be sending to my alternate location instead of my primary location (and I'd still get the mail, by the way). There are many locations in the country with similar situations.
The NPANXX7.TXT file is a 2-column, comma-delimited table with the following format:
These two files can be used independently, or together to convert an NPA-NXX to PCode. To lookup the taxing jurisdiction information for a given NPA-NXX you would find the NPA-NXX in the NPANXX7.txt file, and obtain the corresponding PCode. The NPA-NXX at Avalara’s Overland Park office is 913-859, so from the data below the PCode is 1249200:
Looking up this PCode yields the taxing jurisdiction of: