National foreword

This British Standard is the UK implementation of ISO 24165‑2:2025.

The UK participation in its preparation was entrusted to Technical Committee IST/12, Financial services.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2025.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 68, Financial services, Subcommittee SC 8, Reference data for financial services.

This second edition cancels and replaces the first edition (ISO 24165‑2:2021), which has been technically revised.

The main changes are as follows:

The scope for digital token identifiers (DTIs) has been extended to include non-fungible tokens (NFTs).
The document now separates DTIs to identify tokens and digital ledger identifiers (DLIs) to identify ledgers (only ledgers that have one or more DTIs linked to them are in the scope of this document).
Anchor block information has been added where genesis block is either not known/lost.
"Functionally fungible group" has been renamed "equivalent digital token group".
Issuer and maintainer have been added as informative, optional fields.
"Native token" has been renamed "protocol token".

A list of all parts in the ISO 24165 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

This corrected version of ISO 24165‑2:2025 incorporates the following corrections:

"Non-fungible token distributed ledger" has been added to Table A.3.

Introduction

With the rise in popularity of peer-to-peer payment systems, these systems rely less on centralized authorities. Instead, they depend on aspects of cryptography, decentralized processing and a distributed network. This network maintains a shared record of transaction activity.

As a result, the need to identify the digital tokens issued, traded, transacted or stored on these networks has grown. Stakeholders in the trading community, service providers, custodians and regulatory bodies have identified numerous use cases where a standard identifier for accounting, research, tracking and management of these digital tokens would improve efficiency and eliminate confusion in the marketplace.

However, the nature of these new types of digital asset means they do not fit within the structure of existing ISO identifiers, in part because they can lack clear reference to an issuing authority and will therefore not be considered the liability of an issuing authority or corporate governing body. These digital assets, in many cases, extend across various regions and monetary governance jurisdictions.

Though these digital assets are sometimes referred to as cryptocurrencies, virtual currencies or digital currencies, the term "currency" has a specific meaning as defined by ISO 4217. This definition is in conflict with the nature of the digital tokens identified in this document due to the reasons described above; namely, the lack of monetary authority and geographic location.

Where traditional financial instruments or currencies are tokenized for electronic exchange and issued by a legal entity including the monetary authority responsible for it, other International Standards, such as ISO 6166 or ISO 4217, can apply. To eliminate confusion for users of this document, care has been taken to provide a clear definition and eligibility criteria for assignment of a digital token identifier (DTI) and digital ledger identifier (DLI).

This document is addressed to applicants seeking to identify digital tokens that conform to the definition provided in ISO 24165‑1. The data elements described in this document are used to distinguish one set of digital tokens and ledgers from another and are, wherever possible, objective and publicly available. Inclusion in the registry and the issuance of an identifier signifies only the existence of the token and/or ledger and its 1:1 relationship to its identifier.

The ISO 24165 series is organized into the following parts:

ISO 24165‑1 describes the method of registration and assignment of a DTI and a DLI.
ISO 24165‑2 describes the data elements required for registration and display on the DTI and DLI registry.

1 Scope

This document defines the data elements included in the registry record and used to establish the 1:1 relationship between a digital token and the identifier assigned according to the method in ISO 24165‑1.

2 Normative references

3 Terms and definitions

4 Constituents of a registry record

4.1 Digital token identifier (DTI)

4.2 Digital ledger identifier

4.3 Classes of information

5 Data elements

5.1 Categories of data elements

5.2 Normative data elements for DTI records

5.3 Informative data elements for DTI records

5.4 Data elements for base record of digital ledger identifier (DLI)

5.5 Normative data elements for base record of DLI

5.6 Informative data elements for base record of DLI

5.7 Data elements for fork record(s) for DLI

5.8 Normative data elements for fork record(s) for DLI

6 Registration authority

6.1 Name and contact details of the registration authority

6.2 Service provision for the registration authority

Bibliography