BMF Lookup Tables
The IRS Business Master File is full of codes. These tables say what each code means. They are the same tables the NCCS pipeline uses to label the data.
How to use them. Each table is a small CSV with a code column and a meaning column. Join it to the matching column in the BMF to replace the code with its label, or just open it to look a code up. Every table has the same vintage, listed below, and is refreshed whenever a code list changes.
Loading the current list…
Reading the manifest
Alongside the CSVs sits a file called _manifest.json. It is the receipt for the publish: the vintage (year and month), when the files were built, the version of the pipeline code, and for every CSV its row count, column names and a checksum. If you need to cite exactly which version of a table you used, quote the vintage and the checksum from the manifest. Older vintages stay available under their own folder, for example lookups/bmf/2026_09/.