New 13-Digit ISBNs

With effect from 1 January 2007, the 10-digit format of the International Standard Book Number (ISBN) will be revised to a 13-digit format. The main purposes of the revision are to increase the numbering capacity of the ISBN system, and to make the ISBN totally compatible with the EAN-13 used for other products and supply chains.

Major Changes to ISBN

1. The ISBN will change from 10 digits to 13 digits on 1 January 2007. 

2. Current ISBNs will be converted to 13 digits by being prefixed with 978 and the check digit recalculated accordingly.

   e.g. ISBN 988-97010-0-6 is converted to ISBN 978-988-97010-0-0

3. The resulting 13-digit number will be identical with the EAN-13 number that is currently encoded in the bar code.

4. The ISBNs that publishers currently have will be converted in this way, including any not currently allocated.

5. As the current ranges of ISBNs are exhausted, new ISBN blocks prefixed by 979 will be issued.

6. Publishers' identifiers are not likely to remain the same for ISBNs under the 979 prefix. For example, the Hong Kong Public Libraries current prefix of "988-97010" will become "978-988-97010". It is unlikely that the Hong Kong Public Libraries will also receive the "979-988-97010" prefix.
7. Bar codes will carry the 13-digit ISBN with hyphenation above the bar code and the same number in EAN-13 format (as a numerical string, without hyphens or spaces) below. An example is shown as follows:

   

Transition to 13-Digit ISBNs for Publishers

1. Publishers are advised to convert the ISBNs in active use as of January 2007 (that includes backlist).
2. New publications after 1 January 2007 should be assigned only the new 13-digit ISBN.
3. For titles published before 1 January 2007, publishers are recommended to print both the 10-digit and 13-digit ISBNs on their publications as follows:
   1. The numbers should appear on the verso of the title page, and on the back cover if there is no bar code, in the following style:
      
      

      ISBN-13:	978-988-97010-0-0
      ISBN-10:	988-97010-0-6

   2. If there is a bar code on the back cover of the book, only the 10-digit ISBN should be printed above the bar code symbol. Users who wish to determine the ISBN-13 based upon the printed bar code and its associated text should rely upon the eye-readable Bookland EAN printed below the bar code.
4. Publishers should review and make necessary changes in their existing systems and databases as soon as possible to accommodate the 13-digit ISBNs.

Conversion Service

Books Registration Office provides free services for local publishers to convert the ISBNs they currently have to the new 13-digit format. To obtain their converted lists, please contact our office at 2180 9145 during office hours.

Frequently Asked Questions

• What happens to ISBNs that have already been obtained by a publisher but are not yet assigned?
  The publisher should continue to use these numbers until they are exhausted but must convert the number format to the new 13-digit standard, prefixed by 978 and the check digit recalculated accordingly.

• Will new ISBNs have to be assigned to products that have already been published?
  No. Existing ISBNs should be converted from the 10-digit format to the 13-digit format (prefixed by 978 and the check digit recalulated) by 1 January 2007. This will apply to records for any title for which transactions may occur and should therefore include out-of-print titles as well as those currently in the catalogue.
  The ISBN and bar code on books will not need to be changed until the book is reprinted, as the bar code already represents the EAN-13 which is the same number as the new 13-digit ISBN.
• May publishers re-use existing 10-digit ISBNs on a new publication by adding a 978 prefix?
  No. The addition of a 978 prefix to a previously used ISBN does not make a new ISBN and for that reason must not be assigned to a new publication.
• Will the ISBNs issued after 1 January 2007 be prefixed by 979?
  No. New ISBN blocks prefixed by 979 will be issued only after the current ranges of ISBNs (i.e. prefixed by 978) are exhausted.
• How to calculate the check digit of the 13-digit ISBN?
  The last digit of the ISBN is the check digit which ranges from 0 to 9. It is calculated using a modulus 10 algorithm as follows:
  
  1. Multiply each of the first 12 digits of the ISBN alternately with 1 and 3;
  2. Add the weighted products to form a total;
  3. Divide the sum of the weighted products of the first 12 digits by 10, determining the remainder;
  4. Subtract the remainder from 10. The resulting difference is the value of the check digit with one exception. If this calculation results in an apparent check digit of 10, the check digit is 0.,
  Example :
  
  

  	Prefix Element			Group Identifier			Publisher Prefix					Title Number	Check Digit	Sum
  ISBN	9	7	8	9	8	8	9	7	0	1	0	7	?	-
  Weight	1	3	1	3	1	3	1	3	1	3	1	3	-	-
  Product	9	21	8	27	8	24	9	21	0	3	0	21	-	151
  9+21+8+27+8+24+9+21+0+3+0+21=151
  151÷10=15  remainder 1
  Check Digit=10–1=9
  In this case, the valid ISBN is 978-988-97010-7-9

• Will I be able to communicate with trading partners using 10-digit ISBNs after 1 January 2007?
  After 1 January 2007 the ISBN will be a 13-digit number, and all mechanical systems will have to accommodate its use in that form. Commercial systems may not support 10-digit ISBNs after that date. In the transitional period, however, arrangements may be made between trading partners to support both formats.
• What are the impacts of changing to the 13-digit ISBN?
  Everyone who records, stores, or exchanges ISBN data in an automated system will have to ensure that those systems can accommodate the 13-digit ISBN format. Publishers, distributors, retailers, and libraries are the main user groups affected by these changes. It will affect software applications such as automated ordering systems, inventory control systems, point-of-sale systems, and library databases.

Enquiries

Books Registration Office, Hong Kong Public Libraries
Leisure and Cultural Services Department

Address: Room 805, Lai Chi Kok Government Offices, 19 Lai Wan Road, Lai Chi Kok, Kowloon
(Mei Foo MTR Station Exit C1)
Telephone: 2180 9145 (ISBNs) / 2180 9146 (Books) / 2742 8981 (Periodicals)
Fax: 2180 9841
E-mail: bro@lcsd.gov.hk

Office Hours:
Monday to Friday                                            08:45 a.m. - 01:00 p.m.
                                                                            02:00 p.m. - 06:00 p.m.
Saturday, Sunday and public holidays         Closed

Remarks
The contents of this webpage are extracted and compiled from the following documents prepared by the International ISBN Agency:

• Guidelines for the Implementation of 13-Digit ISBNs"
• "The New ISBN-13 : Information for Publishers"