ISO 24165-1:2025

International
Standard
ISO 24165-1
Second edition
Digital token identifier (DTI) —
2025-05
Registration, assignment and
structure —
Part 1:
Method for registration and
assignment
Jeton digital — Enregistrement, affectation et structure —
Partie 1: Méthode pour l’enregistrement et l’affectation
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Eligibility criteria for application . 2
4.1 Applicant eligibility requirements . .2
4.2 Digital token eligibility requirement .3
4.3 Digital token identifier issuance for non-fungible digital tokens (NFTs).3
4.4 Digital ledger eligibility requirement .3
4.5 Provisional issuance provision .3
5 Application information . 3
5.1 General .3
5.2 Applicant information .3
5.3 Digital token technical information .4
5.4 Descriptive information .4
6 DLI and DTI code structure . 4
6.1 Constituents .4
6.2 Uniqueness .4
6.3 Display.4
7 Registry components . 4
8 Assignment . 5
9 Registration authority . 5
9.1 Name and contact details of the Registration authority .5
9.2 Service provision for the RA .5
Annex A (normative) Check character calculation . 6
Bibliography . 8

iii
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 document 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 24165-1:2021), 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 standard 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 scope).
— Anchor block information has been added where genesis block is either not known/lost.
— Functionally Fungible Group has been renamed Equivalent Group.
— Addition of Issuer and Maintainer 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.

iv
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 or a 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 conforming to the definition
provided in this document. 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 standard scope has been expanded to include DTI issuance for non-fungible tokens (NFTs), which were
excluded in the 2021 edition of this document.
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 & DLI registry.

v
International Standard ISO 24165-1:2025(en)
Digital token identifier (DTI) — Registration, assignment and
structure —
Part 1:
Method for registration and assignment
1 Scope
This document defines the assignment and generation of a random, unique, fixed-length identifier for digital
tokens in response to a request for registration that conforms to specified application guidelines (see also
ISO 24165-2).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 24165-2, Digital token identifier (DTI) — Registration, assignment and structure — Part 2: Data elements
for registration
ISO/IEC 7064:2003, Information technology — Security techniques — Check character systems
3 Te
...