The Bulgarian National ISSN Centre is the registration authority for the International Standard Serial Number (ISSN) for Bulgaria. Activities of the National ISSN Centre are based on contractual relations with the International ISSN Centre and are in accordance with the Instruction for the Organization and Activities of the National ISSN Centre (available in Bulgarian only), the standard БДС ISO 3297:2010. Information and documentation – International standard serial number and internationaly recognized principles.


The Bulgarian National ISSN Centre:

– Assigns ISSN to continuing resources of various media issued in Bulgaria;

– Records the ISSN identified continuing resources in the ISSN International Register database maintained by the International ISSN Centre in Paris;

– Records Bulgarian online open-access scholarly resources in the ROAD portal;

– Maintains local database of ISSNs assigned;

– Monitors ISSN display on publications.


About the ISSN


ISSN is international identifier for continuing resources* (mainly text-based) whether past, present or to be produced in the foreseeable future. This includes newspapers, journals, magazines, annual publications (e.g. reports, directories, proceedings, etc.), websites, and other on all media – print and electronic.

A separate ISSN is assigned to each separate continuing resource or version of continuing resources on different format  (e.g. print, online, CD/DVD), in different language or different geographic edition etc.

ISSN is not assigned to: individual monographs, sound/video recordings, printed music, advertisement and promotional material, calendars, posters, programs, crosswords/sudoku, personal resources, brochures, materials not publicly available.

*Note: Continuing resource is a resource, on any medium, that is published over time without a predetermined end. Serial publications (an unfinished set of documents, published successively under the same title, for an undetermined period of time, having numerical or chronological designations, e.g. newspapers, journals etc.) and ongoing integrating resources (non-fixed resources that can be updated at any time by adding information or by replacing obsolete information with new information, e.g. website, loose-leaf, data base) are continuing resources.



ISSN is assigned to the constant title of the continuing resource and is used to identify the whole resource/sequence of issues under single title.

A new ISSN is assigned when the title of the continuing resource is significantly changed (by addition, deletion, change or reordering of words in title or change of title language) as well as when it’s medium changes (e.g. print becomes online or CD/DVD or vise versa).

A new ISSN is not assigned in case of changes like: different graphic or color layout of the cover/title page; subtitle change; price change; change of type and size of font; publisher or printing change; change of place of publication, frequency, or chronological designation including when this designation is part of the title.

Once assigned to a continuing resource, an ISSN is permanently linked to its title and can never be reused to identify another continuing resource.

The assignment of an ISSN to a continuing resource, shall not imply any meaning or value as legal evidence with regard to the ownership of rights to that resource.



ISSN provides quick and accurate identification of continuing publications facilitating their ordering, sale, subscription and distribution. It contributes to the registration of the continuing resources in different catalogs and databases and supports search, exchange and automated information processing worldwide. ISSN can also refine the citation of scientific literature, allow for the generation of a bar code based on its digits and increases the popularity of publications through their registration in the international ISSN Register database in Paris.



ISSN is an 8-digit code that takes the form of the acronym ISSN followed by two groups of four digits, separated by a hyphen.

Example: ISSN 0317-8471

ISSN is a digital code without any intrinsic meaning: it does not include any information about the origin or contents of the publication, nor does it guarantees the quality or validity of the contents. Main ISSN role is to identify a publication.


Location and display

For a print publication, the ISSN should be shown:

– preferably, in the upper right corner of the cover,

– failing that, on the pages where editorial information is shown (publisher, frequency, colophon, etc.).


For a publication in electronic media, the ISSN should be shown:

– on the homepage or on the main menu, if it is an online publication,

– on any part visible to the naked eye (microfiche header, CD/DVD label, box, case, etc.), if the publication is on a physical medium.


When displaying the ISSNs of different media versions of a publication together they should be distinguished as follows:

ISSN 1562-6865 (Online)

ISSN 1063-7710 (Print)


Online edition: ISSN 1562-6865

Print edition: ISSN 1063-7710



ISSN assignment policy

ISSNs are assigned free of charge!

For the ISSN assignment the following documents are needed:

  1. Registration form;
  2. Copy of document that identifies the publisher – certificate from court or if registered in the Commercial register it is sufficient to only indicate UIC/BULSTAT in the registration form;
  3. If continuing resource is already published – copies of all published issues have to be submitted to the National library through legal deposit;
  4. If resource is not yet published – publisher has to supply mock of the serial, image of the jacket of CD/DVD or send the final version (in doc, pdf or jpg file formats) of the cover, title page, editorial page (with at least the publisher’s name and address indicated); in this case copies must be submitted through legal deposit after releasing the publication in order to validate the ISSN assigned – if this obligation is not fulfilled, further ISSN requests by the same publisher will be rejected!;
  5. If continuing resource is online – it is not ISSN assigned ahead of publication; website must be completed with all accompanying descriptive information and at least 5 articles of the resource have to be published online in order to assign an ISSN.

Note: ISSN assignment is made via e-mail (by submitting the needed documents to issn@nationallibrary.bg) or on site in the National ISSN Centre at the St. Cyril and St. Methodius National Library (Room 72). ISSN assignment itself takes no more than 1 or 3 working days at the latest provided that all accompanying documents have been filed correctly and all necessary information for the registration has been provided by the publisher. The applicant is solely responsible for the accuracy and validity of the information filled in the registration form! The National ISSN Centre reserves the right not to process incomplete requests or requests contradicting the principles of the system. The National ISSN Centre reserves the right to refuse ISSN assignment to publishers who intentionally provided misleading or incorrect information.

Note: Publishers are obliged to: publish the ISSN in their publication; inform the National ISSN Centre of changes in the title, medium, status, URL of online resource, publishing responsibility or other data associated with their publications in advance; and to supply copies of their publications through legal deposit in regular manner in order to create and maintain up-to-date records in the International ISSN database.

Note also that pursuant to the Bulgarian legal deposit legislation publishers must submit certain number of copies of the circulation of each published issue of their serial to the “Legal Deposit Department” of St. Cyril and St. Methodius National Library. For more details refer to Legal deposit section.


Contact details of the National ISSN Agency:

 Contact person: Radoslava Stefanova

Address: Sofia 1504, 88 Vasil Levski Blvd.

St. Cyril and St. Methodius National Library

Phone: + 359 2 9183 218

E-mail: issn@nationallibrary.bg, issn_nl@abv.bg

Visiting hours: Every working day between 10.00-12.00 and 14.00-16.00