BISAC subject codes Defined.
Definition
BISAC subject codes are the book trade's standard list of subject headings, maintained by the Book Industry Study Group (BISG). Each heading, such as TRAVEL / United States / South / General, has a nine-character code (TRV025070), and retailers, distributors, data services and libraries use them to classify, shelve and search for books.
Sources checked 20 October 2026.
How it works
A heading has two to four levels separated by slashes, starting with a major section such as COMPUTERS or HISTORY. Its code is a three-letter prefix, usually a mnemonic, followed by six digits. BISG publishes the full list free online and releases a new edition each fall. Its guidance is that any item with an ISBN should get a code, that items with no subject, such as a blank journal, take NON000000, and that the code needn't be printed on the book at all. KDP's categories help page describes Amazon's own category tree, from which you pick up to 3 categories, and doesn't mention BISAC.
An example
A guide to road trips across the American South fits TRAVEL / United States / South / General, code TRV025070. If it is also a food guide, BISG suggests repeating the search in other major sections and choosing a second heading there, so the book can be shelved in both places.
Common mistakes
Assuming the categories chosen on KDP are BISAC codes: on Amazon you pick from its own tree. Settling for a General heading when a more specific one fits. And printing the nine-character code on the cover, which BISG recommends against: the code is meant for data exchange between companies, and the words of the heading are what people read.
