020  International Standard Book Number (R)


Contents   Fixed field   0xx   1xx   2xx   3xx   4xx   5xx   6xx   7xx   8xx   9xx

Input Standards

Required if applicable/Required if applicable
1st Indicator  Undefined
blank character  Undefined
2nd Indicator  Undefined
blank character  Undefined
Subfields (R=Repeatable  NR=Nonrepeatable) Input Standards
a International Standard Book Number (NR) Required if applicable/Required if applicable
b Binding information (R) Obsolete. Do not use/Obsolete. Do not use
c Terms of availability (NR) Optional/Optional
z Canceled/invalid ISBN (R) Required if applicable/Required if applicable


Contains the International Standard Book Number (ISBN). Use for terms of availability (e.g., price), canceled ISBNs, invalid ISBNs, and SBNs.

An ISBN is a unique number assigned to an item by its publisher. Each ISBN is a ten- or thirteen-digit number and has four parts: the language group of the country of publication, the publisher, the title, and the check character.

Thirteen-digit ISBNs must begin with either 978 or 979 (a 13-digit EAN beginning with 978 or 979 may be input as a valid ISBN).

If printed in a book, catalog or bibliography, these four parts are usually separated by hyphens. Do not enter the hyphens.

If the final character is an x, enter an uppercase X.

Coding EANs and ISBNs

The table below summarizes how to code EANs and ISBNs.

Number Field 1st Indicator 2nd Indicator Subfield
EAN 024 3 any a
10-digit ISBN 020 blank blank a
13-digit ISBN 020 blank blank a

Entering multiple ISBNs

Use the following guidelines for entering multiple ISBNs:

  • Enter each ISBN in a separate 020 field. Do not repeat subfield a.
  • If a book has ISBNs for both hard cover and paperback editions and if the publishers are the same, enter both ISBNs in separate 020 fields.
  • One volume of a multivolume set. Include both the number for the volume and the set number, if available. Enter the number for the volume first. Use separate 020 fields.

    020     0379005514 (v.1)
    020     0379005506 (set)
  • If you are cataloging a multivolume monograph, enter both the set number and the individual volume numbers, if available. Enter the number for the set first. Use separate 020 fields.
  • Do not enter multiple subfield a's.

The final character of an ISBN is a calculated check character, either numeric, 0–9 or X. It is used to identify and eliminate typographical errors.

When you validate a record containing field 020, the system checks subfield a to verify that the content and length of the ISBN are correct and that the check character matches the calculated check character.

If there is an error in the ISBN (e.g., it is too long or too short, has an incorrect character in any position or an incorrect value in the check digit), the system displays an error message with the ISBN remaining in subfield a. If you made a typographical error, correct the ISBN and validate the record again. If the error message appears again and you transcribed the ISBN exactly, the ISBN is in error. Put the ISBN in subfield z.

Deleting ISBNs

If a record contains two ISBNs and you delete one, the system will regenerate the one you deleted and add it to the record. To avoid this situation, delete both ISBNs.

1st Indicator

Undefined. The 1st indicator position is undefined and contains a blank ( blank character ).
blank character Undefined

2nd Indicator

Undefined. The 2nd indicator position is undefined and contains a blank ( blank character ).
blank character Undefined


ISBD records. Enter the ISBN, terms of availability, and qualifications as prescribed by AACR2. Enter terms of availability and qualifications in subfield c, even if no ISBN is available.

Enter binding information for all types of binding other than regular hardbound in subfield a following the ISBN, or in subfield z following the invalid ISBN. Enter all binding information in parentheses. See the Library of Congress Rule Interpretation 1.8 for more information.

If no ISBN, enter binding information in subfield c following the price.

Non-ISBD records. Abbreviate binding information and enter it in parentheses in subfield a, following the ISBN. Enter a space between the binding information and the ISBN. Do not enter binding identification for standard trade editions.

020     2214306080 (pbk.)
020     0819305030 (library)
a International Standard Book Number You may also use subfield a for a qualification (e.g., binding information).
b Binding information Obsolete. Do not use.

Note: Subfield b was valid for BKS, MAP and SCO formats only.

c Terms of availability ISBD records. Enter price information in subfield c.

Non-ISBD records. Do not enter any price information.

020     0700013288 : c $5.95
020     0700014586 (pbk.) z 0700014592 : c $1.95
020     0842270884 (v. 1)
020     9780842270885 (v. 1)
020     0842281215 (v. 2) : c $7.95
020     2214306080 (pbk.) : c $5.95
020     3878779798 (v. 1) z 3878770970 z 3878773453
020     c $1.00 (pbk.)
020     z 0714640016 (pbk. : v. 1) : c $12.00
z Canceled/invalid ISBN ISBNs can be invalid in two ways:
  • Structurally invalid:
    • ISBNs whose check character does not agree with the calculated check character are invalid.
    • ISBNs that do not have exactly ten or thirteen characters are invalid.
  • Application invalid. An ISBN is considered to be application invalid for a particular record when it appears on the bibliographic item, but it is known, through research or other means, that the same number is also assigned to a different resource.


Field 020 subfield a prints as the last note following notes printed from the 5xx Fields. Subfields b, c and z do not print.

If subfield a is not present, no data from field 020 prints. If an ISBN in subfield a has fewer or more than ten digits or has a letter other than X as the tenth character, the ISBN does not print.

The print program supplies the display constant ISBN before the number in subfield a. The print program supplies hyphens within the ISBN, according to the following algorithm. You must enter all other punctuation for printing.

13-digit ISBNs only (if 10-digit, start in next column) 1st digit in range 2nd–5th digits in range Hyphens inserted after
978-979 0–6 0000–1999 1st, 3rd, 9th digits
0–6 2000–6999 1st, 4th, 9th digits
0, 2–6 7000–8499 1st, 5th, 9th digits
0, 2– 8500–8999 1st, 6th, 9th digits
0, 2–6 9000–9499 1st, 7th, 9th digits
0, 2–6 9500–9999 1st, 8th, 9th digits
1 5500–8697 1st, 7th, 9th digits
1 8698–9989 1st, 8th, 9th digits
1 No hyphenation algorithm available. These ISBNs print as a block of digits without hyphens.

Printing multiple 020 fields

Only the first 020 field prints. If the first 020 does not print, no ISBN prints, even if a subsequent 020 field has a valid number in subfield a .

Field 020 Prints as
0713116463 ISBN 0-7131-1646-3
0901212040 (v. 38) ISBN 0-901212-04-0 (v. 38)
2214306080 ISBN 2-214-30608-0
0684142590 (v. 1) : c $89.50 06841424700 (v.2) : c $69.95 ISBN 0-684-14258-9 (v. 1) [Second 020 does not print]
1556530390 ISBN 1-55653-039-0
0684142589 (bound) : c $12.50 0684142470 (pbk) : c $6.95 ISBN 0-684-14258-9 (bound) [Second 020 does not print]

Standard Book Numbers

Some records still use Standard Book Numbers (the forerunner of modern ISBNs). If the item was published in Australia, Canada, New Zealand, Zimbabwe, South Africa, the United Kingdom, or the United States, enter an initial 0 before the Standard Book Number (SBN). Enter the SBN in subfield a . Enter SBNs from other countries in subfield z .

For example, if the SBN is 717803139, enter:


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