From Longman Dictionary of Contemporary Englishbe on the booksbe on the booksif a law is on the books, it is part of the set of laws in a country, town, area etc → book
Examples from the Corpus
be on the books• The five-bedroom house is on the books of Jackson-Stops & Staff with Stimsons at £250,000.• No company had yet lost government business for failure to comply, but the law was on the books.• No such district-wide resolution is on the books for clothing that promotes alcohol. 