Last Updated on July 16, 2026 by Dr. Bhagat
Research Guides·Updated June 2026
What Is an ISSN? Meaning, Format, and How Journals Get One
The eight-digit number on every journal — what it actually means, what it does not guarantee, and how to spot fake ones.
DefinitionWhat ISSN actually is
ISSN stands for International Standard Serial Number. It is an eight-digit code used to uniquely identify serial publications — any publication issued in successive parts, including academic journals, magazines, newspapers, and newsletters.
The ISSN system was established by ISO Standard 3297 in 1975 and is managed through a global network of national ISSN centers in over 90 countries. The ISSN International Centre is headquartered in Paris.
FormatUnderstanding the eight digits
The ISSN format is: XXXX-XXXX. Eight digits total, split into two groups of four by a hyphen. The last digit is a check digit (0–9 or X, where X represents 10) calculated using a specific algorithm to detect transcription errors.
The first seven digits are sequentially assigned. They carry no inherent meaning about the journal’s subject, country, or quality. The check digit ensures that simple transcription errors are caught when the number is entered into databases.
| Component | Description |
|---|---|
| First 7 digits | Sequentially assigned, no encoded meaning |
| Check digit | 0–9 or X; validates the number via mod-11 algorithm |
| Hyphen | Separates the two groups of four digits |
Source: ISSN International Centre, ISO 3297
RegistrationHow journals get an ISSN
Journals apply for an ISSN through their national ISSN center. The process is administrative, not evaluative. The center verifies that the publication is a serial and assigns a number. There is no quality review, no peer review requirement, and no indexing check.
This is the critical point that many researchers misunderstand: an ISSN is an identifier, not a quality certification. A predatory journal can have a perfectly valid ISSN. A top-tier journal and a fake journal can both have ISSNs assigned by the same national center.
LookupHow to verify an ISSN
You can verify an ISSN through the ISSN Portal at portal.issn.org. Enter the ISSN or journal title to see the registered record. This helps you confirm that the number is genuine and matches the journal name.
Predatory journals sometimes invent ISSNs or use numbers assigned to other publications. A quick portal check can catch these fakes in seconds.
If a journal lists an ISSN but it does not appear in the ISSN Portal, or the portal record shows a different journal name, the ISSN is likely fake or misappropriated. Treat the journal as highly suspicious.
Key Takeaways
- An ISSN is an eight-digit identifier for serial publications, not a quality seal.
- The format is XXXX-XXXX with a check digit as the last character.
- Registration is administrative; there is no peer review or quality evaluation.
- Predatory journals can and do have valid ISSNs.
- Always verify an ISSN in the ISSN Portal and check the journal in a quality index.
FAQPeople also ask
Does an ISSN mean a journal is legitimate?
No. An ISSN is purely an identifier. It confirms the publication has been registered as a serial, not that it is peer-reviewed, indexed, or ethical.
How is an ISSN different from an ISBN?
An ISBN identifies a single book or monograph. An ISSN identifies a continuing serial publication like a journal or magazine. They serve different purposes and use different numbering systems.
Can a journal have two ISSNs?
Yes. Journals that publish in both print and electronic formats often have two ISSNs: a p-ISSN for the print version and an e-ISSN for the electronic version. Both are valid and should be registered.
How do I apply for an ISSN?
Contact your national ISSN center through the ISSN International Centre website. The process is free in most countries and requires proof that the publication is a serial.
Can predatory journals fake an ISSN?
Yes. Some invent numbers that do not exist, while others use ISSNs assigned to different journals. Always verify in the ISSN Portal before trusting an ISSN on a journal’s website.
SourcesReferences & further reading
FAQFrequently Asked Questions About ISSN
Is an ISSN a guarantee of journal quality?
No. An ISSN is simply a registration number for serial publications. It does not indicate peer review, editorial standards, or indexing in major databases. Many predatory journals have valid ISSNs.
How long does it take to get an ISSN?
The processing time varies by country but typically takes 2–8 weeks. National ISSN centers process applications in the order received.
Can a journal have both a print ISSN and an online ISSN?
Yes. Journals that publish in both print and electronic formats receive separate ISSNs for each medium. The print ISSN and e-ISSN are linked in the ISSN Register.
How can I verify if an ISSN is genuine?
Check the ISSN Portal maintained by the ISSN International Centre. Enter the ISSN to verify registration details, title, and publisher information.
Pro TipsHow Researchers Use ISSN in Practice
Tip 1: Always check both ISSN and indexing status. When evaluating a journal, verify its ISSN on the official portal AND confirm it is indexed in Scopus, Web of Science, or the DOAJ.
Tip 2: Be wary of journals that prominently display an ISSN as a badge of quality. Predatory journals often feature their ISSN prominently on homepages to create a false impression of legitimacy.
Tip 3: Use the ISSN to search library databases. Many university library catalogs allow ISSN searches, which is the most precise way to find a journal’s holdings and access options.