Guide
Editions, ISBNs, and why the barcode changed
Updated 1 October 2026
What an ISBN does and does not identify, including 978 and 979 numbers and title changes between countries.
The barcode on a book is an identifier for a product. It is not a summary of the story, and it is not stable across the life of a novel. Publishers assign a new ISBN when they issue a new edition: paperback, hardcover, annotated, film tie-in, large print. If you record only one number and treat it as the book, you will miss every other printing. If you ignore numbers entirely, you cannot tell two printings apart when you need to.
ISBN-10, ISBN-13, 978 and 979
Older books carry a 10-digit ISBN. Newer barcodes are 13 digits and usually begin with 978. A 978 number can be converted to the older 10-digit form. That conversion is math, and Book Ledger uses it when it builds an Amazon link for a 978 book. A barcode that begins with 979 does not convert to an ISBN-10. It has to be searched as itself. Typing the digits with or without hyphens does not change the number. Hyphens are punctuation for humans.
The number on the copyright page and the number in the barcode should match. If they do not, trust the page and look again. Some boxes and outer jackets belong to a set, while the book in your hand has its own ISBN. Record the book you can hold.
Same story, different title
Titles move between countries. Harry Potter and the Philosopher's Stone is the UK title of the novel Scholastic published as Harry Potter and the Sorcerer's Stone. The Colour of Magic is often The Color of Magic on US editions. Those are the same works for the purpose of your shelf. A duplicate check that only compares exact title strings will miss them. A duplicate check that only compares ISBNs will also miss them, because the editions do not share a barcode.
Book Ledger treats an exact ISBN as proof you own that printing. It treats a matching core title plus an overlapping author as a likely other edition, and it shows you the copy already on the shelf. You decide whether the new jacket is worth owning. The app does not merge them into one record unless you say they are the same book by simply not adding the second one.
What to write down
- Keep the ISBN when you have it. It is the best way to talk to a shop about a specific printing.
- Keep the title and author even when you have the ISBN. They are how you search when the reprint has a new number.
- For translations, write the translator in the note. The Odyssey without a translator is not a specific book you can repurchase.
- For series, write the title of the novel. Volume numbers are not stable across publishers.
Lookup services sometimes return the wrong edition photo or a different author's book that shares a short title. Look at the author before you save. Book Ledger asks Open Library first and Google Books after that, and you can always type a book by hand when the barcode leads nowhere. A hand-entered book with a correct title is a better record than a scanned book attached to the wrong writer.
When you shop online, the number in the listing should match the edition you mean. A search for the title alone will mix every printing. Paste the ISBN from your record if you are replacing a damaged copy and want that printing again. Search the title and author if any readable copy will do.