The International Book Number (ISBN) is a 10-digit number that uniquely identifies books published internationally. The ISBN system was established in 1968 as a standard identification system and is used to identify a title or edition of a title from a specific publisher. Each number is unique to that edition, ie: a hardcover, CD, or eBook format of the same title would each have their own unique number. Today all book databases use this system making marketing and distribution far more efficient.

If you are publishing a book and want to make sales to bookstores or simply want people to be able to find your book you will need an ISBN. Without this number your book will not be recognized in the book databases and this would undoubtedly hurt your sales.

Every number consists of ten digits preceded by the letters ISBN. The ten-digit number is divided into four parts, each part separated by a hyphen.

There are four parts to the number. (Example: (ISBN) 1-22065-024-6) The first number (1) is the group or country identifier which identifies a national or geographic grouping of publishers. The second number (22065) identifies a particular publisher. The third number (024) identifies a specific title or edition of a title. The fourth number (4) is the check digit arrived at by following a special algorithm.

Publishers, e-book publishers, audio cassette and video producers, software producers, museums and associations with publishing programs.

Numbers are assigned by ISBN group agencies worldwide coordinated by the International Agency in Berlin. Numbers are assigned in the United States by the U.S. ISBN Agency. R.R. Bowker is the independent agent in the U.S. for this system. http://www.bowker.com/bowkerweb/

In the United States contact:
R.R. Bowker
121 Chanlon Road
New Providence, NJ 07974
Phone (908) 665-6770 Fax (908) 665-2895
You can download the application form or apply online here:
http://www.isbn.org/standards/home/isbn/us/secureapp.asp

In Canada contact:
The National Library of Canada
395 Wellington Street
Ottawa, ON
Phone: (819) 994-6872 Fax: (819) 997-7517
Email: isbn@nlc-bnc.ca

In the United Kindom contact:
The UK ISBN Agency
12 Dyott Street
London WC1A 1DF
Phone:(+44 )0207420 6008

The cost of a block of numbers depends on the country in which you're applying. Generally you will receive a block of 10 numbers, but larger blocks are available upon request.

Generally allow 10 business days from the time an ISBN application is received at the agency (not from the date sent by the publisher.) Priority processing is available in two business days from receipt of application. Express processing is 24 business hours.

The ISBN should be printed on the copyright page, and in the lower right hand corner of the back cover of your book. You should use a font size between 9 and 12 points. The number should also appear on the upper edge of the left hand flap of a dust cover. For disks and cassettes, the number should be printed on the label. Once assigned, an ISBN can never be reused.