Publishers are responsible for assigning publication elements to the individual items they publish and for ensuring the application of pertinent regulations. They may apply for and receive a registrant element from a national ISBN registration agency together with a printout or electronic file of the individual ISBNs that are available to them within the allocated registrant element. Some national ISBN registration agencies may charge a fee for these services. 

The national ISBN registration agency will determine the range of publication elements that will be available to the publisher. The range assigned will be determined based on current and anticipated future publication output and is directly related to the length of the registrant element allocated. The publisher should ensure that the national ISBN registration agency has as much information as possible about all available backlist publications and should advise the agency of all present and future publications in order for the assignment of a suitably sized registrant element. 

The publisher should supply the national ISBN registration agency (or its designated local bibliographic agency) with a specified amount of metadata about the publication to which the ISBN is assigned. The specifications concerning the type and format of the metadata are established by the International ISBN Agency in cooperation with the national ISBN registration agencies. The specifications are available here.

In addition on behalf of the International ISBN Agency, EDItEUR has developed an ONIX for ISBN registration format to be used by ISBN registrants (primarily publishers) and national ISBN Agencies. The format is specifically designed to make high-volume ISBN registrations more efficient. Overview documentation and an XSD schema are available from EDItEUR, but please check with your national ISBN agency before submitting your data to them in this format.

Further information and detailed instructions concerning the ISBN system are available from the appropriate national ISBN registration agency.