TheInternational Standard Book Number (ISBN) is a numeric commercialbookidentifier that is intended to be unique.[a][b] Publishers purchase or receive ISBNs from an affiliate of the International ISBN Agency.[2]
A different ISBN is assigned to each separate edition and variation of a publication, but not to a simple reprinting of an existing item. For example, ane-book, apaperback and ahardcover edition of the samebook must each have a different ISBN, but an unchanged reprint of the hardcover edition keeps the same ISBN. The ISBN is ten digits long if assigned before 2007, and thirteen digits long if assigned on or after 1 January 2007.[c] The method of assigning an ISBN is nation-specific and varies between countries, often depending on how large the publishing industry is within a country.
The first version of the ISBN identification format was devised in 1967, based upon the 9-digitStandard Book Numbering (SBN) created in 1966. The 10-digit ISBN format was developed by theInternational Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108 (any 9-digit SBN can be converted to a 10-digit ISBN by prefixing it with a zero).
Privately published books sometimes appear without an ISBN. The International ISBN Agency sometimes assigns ISBNs to such books on its own initiative.[4]
The Standard Book Number (SBN) is a commercial system using nine-digitcode numbers to identify books. In 1965, British bookseller and stationersWHSmith announced plans to implement a standard numbering system for its books.[1] They hired consultants to work on their behalf, and the system was devised byGordon Foster, emeritus professor of statistics atTrinity College Dublin.[5] TheInternational Organization for Standardization (ISO) Technical Committee on Documentation sought to adapt the British SBN for international use. The ISBN identification format was conceived in 1967 in the United Kingdom byDavid Whitaker[6][7] (regarded as the "Father of the ISBN")[8] and in 1968 in the United States by Emery Koltay[6] (who later became director of the U.S. ISBN agencyR. R. Bowker).[8][9][10]
The 10-digit ISBN format was developed by the ISO and was published in 1970 as international standard ISO 2108.[1][6] The United Kingdom continued to use the nine-digit SBN code until 1974. ISO has appointed the International ISBN Agency as theregistration authority for ISBN worldwide and the ISBN Standard is developed under the control of ISO Technical Committee 46/Subcommittee 9TC 46/SC 9. The ISO on-line facility only refers back to 1978.[11]
Total number of ISBN registrations. 2020.
An SBN may be converted to an ISBN by prefixing the digit "0". For example, the second edition ofMr. J. G. Reeder Returns, published by Hodder in 1965, has"SBN 340 01381 8", where "340" indicates thepublisher, "01381" is the serial number assigned by the publisher, and "8" is thecheck digit. By prefixing a zero, this can be converted toISBN0-340-01381-8; the check digit does not need to be re-calculated. Some publishers, such asBallantine Books, would sometimes use 12-digit SBNs where the last three digits indicated the price of the book;[12] for example,Woodstock Handmade Houses had a 12-digit Standard Book Number of 345-24223-8-595 (valid SBN: 345-24223-8, ISBN: 0-345-24223-8),[13] and it costUS$5.95.[14]
TheUnited States, with 3.9 million registered ISBNs in 2020, was by far the biggest user of the ISBN identifier in 2020, followed by theRepublic of Korea (329,582),Germany (284,000),China (263,066), theUK (188,553) andIndonesia (144,793). Lifetime ISBNs registered in the United States are over 39 million as of 2020.[16]
Overview
A separate ISBN is assigned to each edition and variation (except reprintings) of a publication. For example, an ebook,audiobook, paperback, and hardcover edition of the same book must each have a different ISBN assigned to it.[17]: 12 The ISBN of an electronic publication is often colloquially called "eISBN",[18][19] however no such notation is present in the documentation. Whether a publication is electronic or print cannot be inferred from the ISBN only. The ISBN is thirteen digits long if assigned on or after 1 January 2007, and ten digits long if assigned before 2007.[c][3] An International Standard Book Number consists of four parts (if it is a 10-digit ISBN) or five parts (for a 13-digit ISBN).
Section 5 of the International ISBN Agency's official user manual[17]: 11 describes the structure of the 13-digit ISBN, as follows:
The parts of a 10-digit ISBN and the corresponding EAN‑13 and barcode. Note the different check digits in each. The part of the EAN‑13 labeled "EAN" is theBookland country code.
for a 13-digit ISBN, a prefix element – aGS1 prefix: so far 978 or 979 have been made available by GS1,
theregistration group element (language-sharing country group, individual country or territory),[d]
A 13-digit ISBN can be separated into its parts (prefix element,registration group,registrant,publication andcheck digit), and when this is done it is customary to separate the parts withhyphens or spaces. Separating the parts (registration group,registrant,publication andcheck digit) of a 10-digit ISBN is also done with either hyphens or spaces. Figuring out how to correctly separate a given ISBN is complicated, because most of the parts do not use a fixed number of digits.[e] Online tools such the ISBN Converter provided by theLibrary of Congress and ISBNBarcode.org can assist with hyphenation and generate standard barcodes.[21][22]
Issuing process
ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for that country or territory regardless of the publication language. The ranges of ISBNs assigned to any particular country are based on the publishing profile of the country concerned, and so the ranges will vary depending on the number of books and the number, type, and size of publishers that are active. Some ISBN registration agencies are based in national libraries or within ministries of culture and thus may receive direct funding from the government to support their services. In other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded.[23]
A full directory of ISBN agencies is available on the International ISBN Agency website.[24] A list for a few countries is given below:
The ISBNregistration group element is a 1-to-5-digit number that is valid within a single prefix element (i.e. one of 978 or 979),[17]: 11 and can be separated between hyphens, such as"978-1-...". Registration groups have primarily been allocated within the 978 prefix element - many inherited from the 10 digit ISBN.[45] The single-digit registration groups within the 978-prefix element are: 0 or 1 for English-speaking countries; 2 for French-speaking countries; 3 for German-speaking countries; 4 for Japan; 5 for Russian-speaking countries; and 7 for People's Republic of China. Example 5-digit registration groups are 99936 and 99980, for Bhutan. The allocated registration groups are: 0–5, 600–631, 65, 7, 80–94, 950–989, 9910–9989, and 99901–99993.[46] Books published in rare languages typically have longer group elements.[47]
Within the 979 prefix element, the registration group 0 is reserved for compatibility withInternational Standard Music Numbers (ISMNs), but such material is not actually assigned an ISBN.[48] The registration groups within prefix element 979 that have been assigned are 8 for the United States of America, 10 for France, 11 for the Republic of Korea, and 12 for Italy.[49]
The original 9-digit standard book number (SBN) had no registration group identifier, but prefixing a zero to a 9-digit SBN creates a valid 10-digit ISBN.
Registrant element
The national ISBN agency assigns the registrant element (cf.Category:ISBN agencies) and an accompanying series of ISBNs within that registrant element to the publisher; the publisher then allocates one of the ISBNs to each of its books. In most countries, a book publisher is not legally required to assign an ISBN, although most large bookstores only handle publications that have ISBNs assigned to them.[50][51][52]
The International ISBN Agency maintains the details of over one million ISBN prefixes and publishers in theGlobal Register of Publishers.[53] This database is freely searchable over the internet.
Publishers receive blocks of ISBNs, with larger blocks allotted to publishers expecting to need them; a small publisher may receive ISBNs of one or more digits for the registration group identifier, several digits for the registrant, and a single digit for the publication element. Once that block of ISBNs is used, the publisher may receive another block of ISBNs, with a different registrant element. Consequently, a publisher may have different allotted registrant elements. There also may be more than one registration group identifier used in a country. This might occur once all the registrant elements from a particular registration group have been allocated to publishers.
By using variable block lengths, registration agencies are able to customise the allocations of ISBNs that they make to publishers. For example, a large publisher may be given a block of ISBNs where fewer digits are allocated for the registrant element and many digits are allocated for the publication element; likewise, countries publishing many titles have few allocated digits for the registration group identifier and many for the registrant and publication elements.[54] Here are some sample ISBN-10 codes, illustrating block length variations.
ISBN
Country or area
Publisher
99921-58-10-7
Qatar
NCCAH, Doha
9971-5-0210-0
Singapore
World Scientific
960-425-059-0
Greece
Sigma Publications
80-902734-1-6
Czech Republic; Slovakia
Taita Publishers
85-359-0277-5
Brazil
Companhia das Letras
1-84356-028-3
English-speaking area
Simon Wallenberg Press
0-684-84328-5
English-speaking area
Scribner
0-8044-2957-X
English-speaking area
Frederick Ungar
0-85131-041-9
English-speaking area
J. A. Allen & Co.
93-86954-21-4
English-speaking area
Edupedia Publications Pvt Ltd.
0-943396-04-2
English-speaking area
Willmann–Bell
0-9752298-0-X
English-speaking area
KT Publishing
English-language pattern
English-language registration group elements are 0 and 1 (2 of more than 220 registration group elements). These two registration group elements are divided into registrant elements in a systematic pattern, which allows their length to be determined, as follows:[20]
Acheck digit is a form of redundancy check used forerror detection, the decimal equivalent of a binarycheck bit. It consists of a single digit computed from the other digits in the number. The method for the 10-digit ISBN is an extension of that for SBNs, so the two systems are compatible; an SBN prefixed with a zero (the 10-digit ISBN) will give the same check digit as the SBN without the zero. The check digit is base eleven, and can be an integer between 0 and 9, or an 'X'. The system for 13-digit ISBNs is not compatible with SBNs and will, in general, give a different check digit from the corresponding 10-digit ISBN, so does not provide the same protection against transposition. This is because the 13-digit code was required to be compatible with theEAN format, and hence could not contain the letter 'X'.
ISBN-10 check digits
According to the 2001 edition of the International ISBN Agency's official user manual,[55] the ISBN-10 check digit (which is the last digit of the 10-digit ISBN) must range from 0 to 10 (the symbol 'X' is used for 10), and must be such that the sum of the ten digits, each multiplied by its (integer) weight, descending from 10 to 1, is a multiple of 11. That is, ifxi is theith digit (numbering from left to right), thenx10 must be chosen such that:
It is also true for ISBN 10s that the sum of all ten digits, each multiplied by its weight inascending order from 1 to 10, is a multiple of 11. For this example:
Formally, this is rendered
The two most common errors in handling an ISBN (e.g. when typing it or writing it down) are a single altered digit or the transposition of adjacent digits. It can be proven mathematically that all pairs of valid ISBN 10s differ in at least two digits. It can also be proven that there are no pairs of valid ISBN 10s with eight identical digits and two transposed digits (these proofs are true because the ISBN is less than eleven digits long and because 11 is aprime number). The ISBN check digit method therefore ensures that it will always be possible to detect these two most common types of error, i.e., if either of these types of error has occurred, the result will never be a valid ISBN—the sum of the digits multiplied by their weights will never be a multiple of 11. However, if the error were to occur in the publishing house and remain undetected, the book would be issued with an invalid ISBN.[56]
In contrast, it is possible for other types of error, such as two altered non-transposed digits, or three altered digits, to result in a valid ISBN (although it is still unlikely).
ISBN-10 check digit calculation
Each of the first nine digits of the 10-digit ISBN—excluding the check digit itself—is multiplied by its (integer) weight, descending from 10 to 2, and the sum of these nine products found. The value of the check digit is simply the one number between 0 and 10 which, when added to this sum, means the total is a multiple of 11.
For example, the check digit for an ISBN-10 of 0-306-40615-? is calculated as follows:
Adding 2 to 130 gives a multiple of 11 (because 132 = 12×11)—this is the only number between 0 and 10 which does so. Therefore, the check digit has to be 2, and the complete sequence is ISBN 0-306-40615-2. If the value of required to satisfy this condition is 10, then an 'X' should be used.
Alternatively,modular arithmetic is convenient for calculating the check digit using modulus 11. Theremainder of this sum when it is divided by 11 (i.e. its value modulo 11), is computed. This remainder plus the check digit must equal either 0 or 11. Therefore, the check digit is (11 minus the remainder of the sum of the products modulo 11) modulo 11. Taking the remainder modulo 11 a second time accounts for the possibility that the first remainder is 0. Without the second modulo operation, the calculation could result in a check digit value of11 − 0 = 11, which is invalid. (Strictly speaking, thefirst "modulo 11" is not needed, but it may be considered to simplify the calculation.)
For example, the check digit for the ISBN of 0-306-40615-? is calculated as follows:
Thus the check digit is 2.
It is possible to avoid the multiplications in a software implementation by using two accumulators. Repeatedly addingt intos computes the necessary multiples:
// Returns ISBN error syndrome, zero for a valid ISBN, non-zero for an invalid one.// digits[i] must be between 0 and 10.intCheckISBN(intconstdigits[10]){inti,s=0,t=0;for(i=0;i<10;++i){t+=digits[i];s+=t;}returns%11;}
The modular reduction can be done once at the end, as shown above (in which cases could hold a value as large as 496, for the invalid ISBN 99999-999-9-X), ors andt could be reduced by a conditional subtract after each addition.
ISBN-13 check digit calculation
Appendix 1 of the International ISBN Agency's official user manual[17]: 33 describes how the 13-digit ISBN check digit is calculated. The ISBN-13 check digit, which is the last digit of the ISBN, must range from 0 to 9 and must be such that the sum of all the thirteen digits, each multiplied by its (integer) weight, alternating between 1 and 3, is a multiple of10. As ISBN-13 is a subset ofEAN-13, the algorithm for calculating the check digit is exactly the same for both.
The calculation of an ISBN-13 check digit begins with the first twelve digits of the 13-digit ISBN (thus excluding the check digit itself). Each digit, from left to right, is alternately multiplied by 1 or 3, then those products are summedmodulo 10 to give a value ranging from 0 to 9. Subtracted from 10, that leaves a result from 1 to 10. A zero replaces a ten, so, in all cases, a single check digit results.
For example, the ISBN-13 check digit of 978-0-306-40615-? is calculated as follows:
Thus, the check digit is 7, and the complete sequence is ISBN 978-0-306-40615-7.
In general, the ISBN check digit is calculated as follows.
Let
Then
This check system—similar to theUPC check digit formula—does not catch all errors of adjacent digit transposition. Specifically, if the difference between two adjacent digits is 5, the check digit will not catch their transposition. For instance, the above example allows this situation with the 6 followed by a 1. The correct order contributes3 × 6 + 1 × 1 = 19 to the sum; while, if the digits are transposed (1 followed by a 6), the contribution of those two digits will be3 × 1 + 1 × 6 = 9. However, 19 and 9 are congruent modulo 10, and so produce the same, final result: both ISBNs will have a check digit of 7. The ISBN-10 formula uses theprime modulus 11 which avoids this blind spot, but requires more than the digits 0–9 to express the check digit.
Additionally, if the sum of the 2nd, 4th, 6th, 8th, 10th, and 12th digits is tripled then added to the remaining digits (1st, 3rd, 5th, 7th, 9th, 11th, and 13th), the total will always be divisible by 10 (i.e., end in 0).
ISBN-10 to ISBN-13 conversion
A 10-digit ISBN is converted to a 13-digit ISBN by prepending "978" to the ISBN-10 and recalculating the final checksum digit using the ISBN-13 algorithm. The reverse process can also be performed, but not for numbers commencing with a prefix other than 978, which have no 10-digit equivalent.
Errors in usage
Publishers andlibraries have varied policies about the use of the ISBN check digit. Publishers sometimes fail to check the correspondence of a book title and its ISBN before publishing it; that failure causes book identification problems for libraries, booksellers, and readers.[57] For example,ISBN0-590-76484-5 is shared by two books—Ninja gaiden: a novel based on the best-selling game by Tecmo (1990) andWacky laws (1997), both published byScholastic.
Most libraries and booksellers display the book record for an invalid ISBN issued by the publisher. The Library of Congress catalogue contains books published with invalid ISBNs, which it usually tags with the phrase "Cancelled ISBN".[58] The International Union Library Catalog (WorldCatOCLC—Online Computer Library Center system) often indexes by invalid ISBNs, if the book is indexed in that way by a member library.[59]
EAN format used in barcodes, and upgrading
Thebarcodes on a book's back cover (or inside a mass-marketpaperback book's front cover) areEAN-13; they may have a separate barcode encoding five digits called anEAN-5 for thecurrency and therecommended retail price.[60] For 10-digit ISBNs, the number "978", theBookland "country code", is prefixed to the ISBN in the barcode data, and the check digit is recalculated according to the EAN-13 formula (modulo 10, 1× and 3× weighting on alternating digits).
Partly because of an expected shortage in certain ISBN categories, theInternational Organization for Standardization (ISO) decided to migrate to a 13-digit ISBN (ISBN-13). The process began on 1 January 2005 and was planned to conclude on 1 January 2007.[61] As of 2011[update], all the 13-digit ISBNs began with 978. As the 978 ISBN supply is exhausted, the 979 prefix was introduced. Part of the 979 prefix is reserved for use with theMusicland code for musical scores with anISMN. The 10-digit ISMN codes differed visually as they began with an "M" letter; the bar code represents the "M" as a zero, and for checksum purposes it counted as a 3. All ISMNs are now thirteen digits commencing 979-0, while 979-1 to 979-9 are used for ISBN, 979-8- used for USA.
Publisher identification code numbers are unlikely to be the same in the 978 and 979 ISBNs, likewise, there is no guarantee that language area code numbers will be the same. Moreover, the 10-digit ISBN check digit generally is not the same as the 13-digit ISBN check digit. Because the GTIN-13 is part of theGlobal Trade Item Number (GTIN) system (that includes the GTIN-14, the GTIN-12, and the GTIN-8), the 13-digit ISBN falls within the 14-digit data field range.[62]
Barcode format compatibility is maintained, because (aside from the group breaks) the ISBN-13 barcode format is identical to the EAN barcode format of existing 10-digit ISBNs. So, migration to an EAN-based system allows booksellers the use of a single numbering system for both books and non-book products that is compatible with existing ISBN based data, with only minimal changes toinformation technology systems. Hence, manybooksellers (e.g.,Barnes & Noble) migrated to EAN barcodes as early as March 2005. Although many American and Canadian booksellers were able to read EAN-13 barcodes before 2005, most general retailers could not read them. The upgrading of theUPCbarcode system to full EAN-13, in 2005, eased migration to the ISBN in North America.
VD 16 (Verzeichnis der im deutschen Sprachbereich erschienenen Drucke des 16. Jahrhunderts, "Bibliography of Books Printed in the German Speaking Countries of the Sixteenth Century")
VD 17 (Verzeichnis der im deutschen Sprachraum erschienenen Drucke des 17. Jahrhunderts, "Bibliography of Books Printed in the German Speaking Countries of the Seventeenth Century")
Explanatory notes
^Occasionally, publishers erroneously assign an ISBN to more than one title—the first edition ofThe Ultimate Alphabet andThe Ultimate Alphabet Workbook have the same ISBN, 0-8050-0076-3. Conversely, the same book can be published with several ISBNs: A German second-language edition ofEmil und die Detektive has the ISBNs 87-23-90157-8 (Denmark), 0-8219-1069-8 (United States), 91-21-15628-X (Sweden), 0-85048-548-7 (United Kingdom) and 3-12-675495-3 (Germany).
^In some cases, books sold only as a set share the same ISBN. For example, theVance Integral Edition used only two ISBNs for 44 books.
^abPublishers were required to convert existing ISBNs from the 10-digit format to the 13-digit format (in their publication records) by 1 January 2007. Forexisting publications, the new 13-digit ISBN would only need to be added if (and when) a publication was reprinted. During the transition period, publishers were recommended to printboth the 10-digit and 13-digit ISBNs on the verso of a publication's title page, but they were required to printonly the 13-digit ISBN after 1 January 2007.[3]
^Some books have several codes in the first block: e.g. A. M. Yaglom'sCorrelation Theory..., published bySpringer Verlag, has two ISBNs,0-387-96331-6 and3-540-96331-6. Though Springer's 387 and 540 codes are different for English (0) and German (3); the same item number 96331 produces the same check digit for both (6). Springer uses 431 as the publisher code for Japanese (4), and 4-431-96331-? also has a check digit of 6. Other Springer books in English have publisher code 817, and 0-817-96331-? would also have a check digit of 6. This suggests that special considerations were made for assigning Springer's publisher codes, as random assignments of different publisher codes would not be expected to lead by coincidence to the same check digit every time for the same item number. Finding publisher codes for English and German, say, with this effect would amount to solving a linear equation in modular arithmetic.[original research?]
^The International ISBN Agency'sISBN User's Manual says: "The ten-digit number is divided into four parts of variable length, which must be separated clearly, by hyphens or spaces", although omission of separators is permitted for internal data processing. If present, hyphens must be correctly placed.[20] The actual definition for hyphenation contains more than 220 different registration group elements with each one broken down into a few to several ranges for the length of the registrant element (more than 1,000 total). The document defining the ranges, listed by agency, is 29 pages.
References
^abc"ISBN History". isbn.org. 20 April 2014.Archived from the original on 20 April 2014. Retrieved20 April 2014.
^"Bowker – ISBN". R. R. Bowker. 8 March 2013.Archived from the original on 31 March 2015. Retrieved8 March 2013.
^"ISBN Ranges".isbn-international.org. 29 April 2014. Select the format you desire and click on the Generate button.Archived from the original on 29 April 2014. Retrieved29 April 2014.
^Seea complete list of group identifiersArchived 29 April 2014 at theWayback Machine. ISBN.org sometimes calls themgroup numbers. Their table of identifiers now refers toISBN prefix ranges, which must be assumed to be group identifier ranges.
^Hailman, Jack Parker (2008).Coding and redundancy: man-made and animal-evolved signals. Harvard University Press. p. 209.ISBN978-0-674-02795-4.
^"Independent Publishers".Waterstones.Archived from the original on 9 January 2020. Retrieved2 February 2020.Before submitting any titles to our central buying team for consideration, your book must have the following: An ISBN...
^"How to obtain an ISBN".Barnes & Noble.Archived from the original on 2 February 2020. Retrieved2 February 2020.We use ISBNs to track inventory and sales information. All books Barnes & Noble transacts on must have an ISBN.
^"Product ID (GTIN) requirements for Books". Amazon.com.Archived from the original on 2 February 2020. Retrieved2 February 2020.Effective June 1, 2017, you must provide an ISBN, EAN, or JAN to list a book in the Amazon catalog, regardless of the book's publication date.
^Splane, Lily (2002).The book book : a complete guide to creating a book on your computer (2nd ed.). San Diego, Calif.: Anaphase II.ISBN0-945962-14-2.OCLC54527545.
^Frequently asked questions, United States: ISBN, 12 March 2014, archived fromthe original on 16 April 2014 – including a detailed description of the EAN-13 format.
^"ISBN",ISO TC49SC9 (FAQ), Canada: Collections, archived fromthe original on 10 April 2007, retrieved22 September 2004
