ISIN Services

London Stock Exchange Group (LSEG) is the sole issuer for International Securities Identification Numbers (ISIN), Financial Instrument Short Name (FISN) and Classification of Financial Instruments (CFI) Codes for Great Britain, Jersey, Guernsey and the Isle of Man.

Access accurate, timely and reliable ISIN codes

With over 25 years’ experience in issuing accurate, timely and reliable ISIN codes to the market as the UK’s National Numbering Agency.

Being a founding member of the Association of National Numbering Agencies (ANNA), we aim to uphold the use of standard identifiers to make the financial world a more efficient, safer, and more stable environment for investors and the financial institutions that serve them.

Benefit from LSEG’s pre-allocated service.


London Stock Exchange Plc is the UK National Numbering Agency and a member of ANNA (Association of National Numbering Agencies). Our ISIN allocation jurisdiction covers Great Britain, Jersey, Guernsey & the Isle of Man.

We do not charge a fee for ISIN allocation and neither do we charge a fee for maintenance of the issued ISIN.

Please note, we have no dealings or affiliation with any third parties who offer ISIN application services.

A pop-up advisory note (below) has been issued by ANNA which appears on their website, .

The Association of National Numbering Agencies (ANNA) confirms that only official National Numbering Agencies (NNAs) can issue valid ISINs (International Securities Identification Numbers). The majority of NNAs do not charge for ISIN allocation and fees do not apply for maintenance/renewal of allocated ISINs. In the few instances where fees are charged for ISIN allocation, this is on a cost-recovery basis only, in accordance with ISO 6166 ISIN Registration Authority obligations. The same applies for CFI (Classification of Financial Instruments) according to ISO 10962 and FISN (Financial Instrument Short Name) according to ISO 18774.

ANNA and NNAs have no dealings or affiliation with any third party offering commercial services for assisting to obtain or maintain ISINs. Similarly, any threats from these organizations to purge a valid ISIN from certain systems if “maintenance fees” or other monies are not paid should be viewed with scepticism. To avoid incurring unnecessary costs, we strongly recommend requesting your ISIN, CFI, and FISN only from an official NNA. The process is very straightforward.

For any assistance in contacting the responsible NNA for your request please contact ANNA directly at Alternatively, contact the NNA responsible for your market to assist with your ISIN request.

The full list of official NNAs and their contact details can be found here.

Our ISIN services

  • All UK ISIN applications must be submitted through the Pegasus Online ISIN Submission website, which is part of our continuing commitment to provide best in class issuer services, facilitating the financial markets with timely and accurate reference data. Pegasus utilises innovative technology to assist with the processing and issuance of ISIN & CFI codes.

    Can I use Pegasus immediately?

    Before you can use the Pegasus Online ISIN Submission website, you will need to register for a free user account on UnaVista.

    Once you have accessed UnaVista, click on the number next to the UK ISIN Search folder, the right-hand pane will load with the folder contents, click the “Request UK ISIN” button at the top which will take you through to the Pegasus Online ISIN Submission website screen. Registration is quick and easy and only needs to be completed once.

    If you have already pre-registered for a UnaVista account and use the same link then you will be prompted to create a different password for the Pegasus Online ISIN Submission website.

    How can I submit my ISIN request through Pegasus after registering?

    ISIN applications can be submitted through the UnaVista website once registered, by clicking on the “Request UK ISIN” button which will take you through to the Pegasus Online ISIN Submission website. Alternatively, you will be able to access ‘Pegasus’ via the direct link on this webpage below.

    Is there a User guide available for Pegasus?

    Yes. A Pegasus User guide and Checklist are available below.

    We believe that applying for an ISIN through Pegasus is very intuitive and straight forward, but should you have any questions please contact us by email at

    ISIN Application Guidance

    This documentation gives details on the ISIN application process and who can apply for an ISIN and what mandatory documentation is required. By submitting a request for an ISIN, the applicant warrants that it has the legal authority to request an identifier on behalf of the issuer of the security that is the subject of the ISIN; and warrants that all information supplied shall be true and correct in all material respects.

    Or alternatively, please reach out to us by email at

    Should you have any queries, including updates or changes to ISINs issued by the London Stock Exchange (Prefix: GB, GG, IM & JE) please contact us by email at

  • The London Stock Exchange and UnaVista offers a bulk ISIN Pre-Allocation Services for organisations who issue their own instruments and require an ISIN code within their instrument creation workflow or for Regulatory compliance.

    ISIN issuance must fall within the parameters of ISO6166 for allocation by the London Stock Exchange Plc acting as the National Numbering Agency for Great Britain, Jersey, Guernsey and the Isle of Man.

    Key benefits

    • Improve your operational efficiency
      Pre-allocation means access to unique, ready to go ISIN codes when you need them, without worrying about duplication or inaccuracy.
    • Near real time allocation
      Our bulk allocation service provides you with the ISIN codes in near real-time, so you don’t have to worry about delays to your processing.
    • Easy to use software
      Our ISIN pre-allocation service is hosted by London Stock Exchange Group’s award winning UnaVista platform, providing users with an easy to use, established platform accessible globally, 247. Please email the ISIN Services Team at and SEDOL sales at for more information.
      • The ISO 18774 standard incorporates the issuer short name and the abbreviated characteristics for the financial instrument. It has a maximum length of 35 alphanumeric characters.
      • Unlike other ISO-standard financial instrument identification codes, the FISN is not meant to be machine-readable, but to provide a short format for essential information about a security for human use.
      • The FISN is composed of:
      • zn “/” as the delimiter between issuer name and instrument description;
      • An issuer name with a maximum length of 15 alphanumeric characters. To ensure uniformity, the same issuer short name should be used for different financial instruments of the same issuer;
      • Exception: in the case of CIVs (Collective Investment Vehicles) issuer name might be longer;
      • An instrument description with a maximum length of 19 alphanumeric characters, assuming that the available length of the issuer name has been fully used. In the event that all the 15 characters have not been used in the issuer short name, the remaining space may be used to describe the characteristics of the financial instrument.
      • The CFI code has been developed to address a number of issues which have affected the financial community:
      • Lack of consistent and uniform approach to grouping financial instruments.
      • Use of similar terminology for instruments with significantly different features in different countries.
      • Inability to group securities in a consistent manner leading to reports of holdings being categorised differently.

      The benefits of the code are:

      • Definition and description for an internationally valid system to classify financial instruments.
      • Provision of a set of codes to be used by all market participants in an EDP environment and permission of electronic communication between participants.
      • Improved understanding of the characteristics of financial instruments will lead to a better understanding by investors.

      The structure of the CFI code:

      • The CFI reflects characteristics that are defined when a financial instrument is issued and remain unchanged during its entire lifetime.
      • The CFI consists of six alphabetical characters. The first character indicates the highest level of classification (categories).


      • Equities (E)
      • Collective investment vehicles (C)
      • Debt instruments (D)
      • Entitlement (rights) (R)
      • Listed options (O)
      • Futures (F)
      • Swaps (S)
      • Non-listed and complex listed options (H)
      • Spot (I)
      • Forwards (J)
      • Strategies (K)
      • Financing (L)
      • Referential instruments (T)
      • Others (miscellaneous) (M)
      • The second character indicates specific groups within each category:

      Groups e.g. for equities:

      • Common/ordinary shares
      • Preferred/preference shares
      • Common/ordinary convertible shares
      • Preferred/preference convertible shares
      • Limited partnership units
      • Depositary receipts on equities
      • Structured instruments (participation)
      • Others (miscellaneous)
      • The third to sixth character indicate the most important attributes to each group:

      Attributes e.g. for equities:

      • Voting right
      • Ownership/transfer restrictions
      • Payment status
      • Form


ISIN code issuance is a free service offered by the LSE.

London Stock Exchange Plc (“The Exchange”) acting in its capacity as the National Numbering Agency (“NNA”) for the United Kingdom and a Full member of the Association of National Numbering Agencies (“ANNA”) is the sole issuer of Great Britain (GB), Jersey (JE), Guernsey (GG) & the Isle of Man (IM) International Securities Identification Numbers (ISINs) pursuant to ISO 6166.

The Exchange shall conduct appropriate due diligence on any request for an ISIN. The determination of whether a security is eligible for an ISIN and whether the requester has supplied appropriate documentation shall be made by The Exchange in its sole discretion and any such determination shall be final. The Exchange may, in its sole discretion and without notice, suspend or deactivate an ISIN(s). The Exchange shall have no liability in connection with a determination that a security is or is not eligible for an ISIN. The allocation of an ISIN to a particular security is not intended to be and should not be construed as an endorsement of such security, or an opinion as to the legal validity of such security.

The Exchange does not guarantee the accuracy, adequateness or completeness of any data associated with the ISIN and shall not be liable or responsible for any errors or omissions or for the results obtained from the use of any ISIN.

By submitting a request for an ISIN, the applicant: (a) warrants that it has the legal authority to request an identifier on behalf of the issuer of the security that is the subject of the ISIN; (b) warrants that all information supplied shall be true and correct in all material respects; and (c) acknowledges and agrees to this disclaimer.

Request details

To learn more about our ISIN services, to register your email for updates and announcements from ISIN team, or to send us a query - please fill in the details and submit the form below.