Frequently Asked Questions
First published: 27 September 2023
This set of FAQs seeks to raise market awareness on the ISO 24165 Digital Token Identifier (DTI) standard by answering fundamental questions on the nature of the identifier and its purpose, among other industry standards, to facilitate market integrity and transparency. Where feasible, the FAQs rely on definitions set out by regulatory bodies and other standard-setting authorities.
Background
The DTI Foundation (DTIF) is a non-profit division of Etrading Software, a financial technology firm with a mission of solving market-wide problems by building market infrastructures for the new digital economy.
As Registration Authority (RA) for the ISO 24165 standard, the DTIF’s mission is to provide the golden source reference data for the unique identification of digital tokens and the distributed ledgers they are deployed on.
DTIF issues and maintains DTIs on a non-profit, cost-recovery basis. The DTI Registry can be searched free of charge on the DTIF website, supporting transparency in the digital asset market. Fees for DTI allocation and for API access to Registry data are set out on the DTI Fees page.
ISO 24165 parts 1 and 2 were developed by the ISO subcommittee SC 8 Reference data for financial services of the ISO/TC 68 Financial Services technical committee. The first edition was published in 2021. The second edition, published in 2025, reflects market feedback and refinements. All existing tokens retain the same DTI, so the second edition is fully backward compatible. See Second Edition Differences.
General
A Digital Token Identifier (DTI) is a global identifier for digital tokens, defined by the International Organization for Standardization in ISO 24165. The first edition was published in 2021 and the second edition in 2025.
A DTI comprises:
- a code: a random, unique combination of nine alphanumeric characters allocated to a digital token, such as X9J9K872S for Ether, the protocol token of Ethereum, and
- a record of data relevant to that token (the reference data), held in the DTI Registry. It covers the token’s technical attributes, such as address, name(s), issuer, maintainer and external identifiers, and the distributed ledger on which it is deployed..
Under the second edition, each distributed ledger is identified by its own Digital Ledger Identifier (DLI). For example, the Ethereum ledger is DLI 9DDKPFN21. A DTI unambiguously links a digital token to the ledger it is deployed on.
The increasing adoption of distributed ledger technology in the traditional financial sector and the rapid growth of the decentralised crypto ecosystem have led to heightened demand by public authorities and market participants for identifying digital tokens within these networks, where they are issued, traded, settled, or stored.
DTIs are needed to provide a standardised and consistent way of identifying and referencing digital tokens across different platforms, systems, and jurisdictions.
The DTI Foundation is responsible for allocating DTI codes as the Registration Authority (RA)2 for the ISO 24165 standard.
The DTI code consists of nine alphanumeric characters with the following structure:
The first eight characters are the base number.
The base number is eight characters in length but excludes vowels (A, E, I, O, U) and the letter Y (zero shall is never a first character).
The base number is randomly generated and semantically meaningless (in cases where a randomly generated identifier inadvertently appears to be semantically meaningful, DTIF would discard it).
The final character is the check character.
Key benefits include:
- Transparency: Identification of the digital token, its location on a public or private blockchain, and link to underlying assets, if relevant.
- Interoperability: Standardised method to distinguish between different ledgers and tokens.
- Uniqueness: DTI is based on the digital token’s unique and verifiable origins on the distributed ledger data structure.
- Consistency: Ability to distinguish original, legitimate tokens from newly created digital tokens following fork events.
- Scalability: A unified token identifier method supports scalability and resilience to the currently fragmented crypto-asset industry.
The scope of DTI use includes all digital assets which use distributed ledger technology for their issuance, storage, exchange, record of ownership, or transaction validation, excluding fiat currencies. Digital assets include, but are not limited to, DLT financial instruments, stablecoins, tokenised deposits, and the wider universe of crypto-assets. DTIs, for example, can be assigned to:
- Security tokens (including both native digital assets and tokenised traditional assets)
- Asset-backed tokens (also known as asset-referenced tokens or stablecoins, and e-money tokens)
- Crypto-assets (based on the FSB’s definition3, also referred to as cryptocurrencies)
The DTI Registry and application process is open to all. Users include:
- Security token market participants to recognise, safekeep, track, and analyse DLT financial instruments.
- Regulators and central banks for enhanced market oversight, insights on at-risk instruments and trades, market abuse and Anti-Money Laundering and Counter-Terrorism Financing supervision.
- Crypto-asset (cryptocurrency) market participants for greater transparency on token tracking and verification.
The party applying for a DTI code must complete the application form provided by the DTI Foundation and enclose the necessary information that is considered to be essential for allocating the DTI code. DTIs are assigned in accordance with ISO 24165-1:2025 and ISO 24165-2:2025. All registration requests submitted via the DTIF website will be verified to ensure that:
- The token exists and is eligible for a DTI
- The token has not already been assigned a DTI
- Normative and/or Informative data supplied by the registrant meets the validation criteria
All requests are usually processed within 24 hours if all relevant information is provided.
Technical
The ISO 24165 series is organised into the following parts:
- ISO 24165-1 describes the method of registration and assignment of a DTI.
- ISO 24165-2 describes the data elements required for registration and display on the DTI registry.
The DTI Registry is publicly available for users to search the list of all allocated DTIs.
A provisional DTI may be assigned prior to the existence of a live token. The DTI will show in the registry with a provisional status. Once live, a verification process will be conducted by the DTIF to update the status from provisional to validated. The DTI code (the unique combination of nine alphanumeric characters) will remain the same and all changes tracked through the registry. If the request is withdrawn, the DTI will be marked as deleted in the registry and the unique identifier will not be used again.
The string of nine alphanumeric characters representing a DTI cannot be changed, modified or re-used once assigned. However, it is possible to request an amendment for other reference data details for an existing record in the registry.
The ISO 24165 standard identifies the following:
- Protocol digital token: a token with a privileged position in a distributed ledger protocol, e.g. Bitcoin (BTC) or Ether (ETH). Referred to as a “native digital token” in the first edition.
- Auxiliary digital token: a token created as an application on a distributed ledger, e.g. ERC-20 tokens.
- Equivalent Digital Token Group (EDTG): a set of digital tokens that are not technically compatible but are considered equivalent, e.g. Tether USD on several networks. The registry records the reason for the grouping. Referred to as a “Functionally Fungible Group” in the first edition.
Distributed ledgers themselves are identified by a Digital Ledger Identifier (DLI). In the first edition, a ledger was identified through its native token, or through a “distributed ledger without a native digital token” DTI type.
A DTI provides linkage across three levels:
- Asset level: tokens representing the same digital asset, which can be grouped as an Equivalent Digital Token Group. Digital asset external identifiers, such as an ISIN, can be recorded.
- Token level: a DTI for a token implemented on a distributed ledger, such as a smart contract (auxiliary digital token) or a protocol token.
- Ledger level: each distributed ledger has a unique Digital Ledger Identifier (DLI).
The equivalent digital token group of digital tokens is a group of tokens that are accepted as equivalent in several use cases. Grouping could be created in several cases, including but not limited to the below scenarios:
- All tokens are issued by the same issuer, and the issuer asserts their fungibility
- A technical process across DLT networks which facilitates interchangeability, such as side-chains and bridges
- Algorithmic fungibility
- Software upgrade of tokens
The DTI complement other identifiers such as the ISO 6166 International Securities Identification Number (ISIN), ISO 4914 Unique Product Identifier (UPI) and ISO 17442 Legal Entity Identifier (LEI).
The below graph illustrates the ISO 24165 standard’s relationship with other relevant ISO standards.
Ecosystem of ISO TC 68 Financial Services standards
An International Securities Identifier Number (ISIN) is a recognised standard for identifying traditional securities, including shares, bonds, options, and other financial instruments. A Digital Token Identifier (DTI) is a recognised standard to identify digital tokens that exist on a distributed ledger.
Within traditional financial markets, ISIN and Market Identifier Code (MIC) codes identify the what and where of a transaction respectively, facilitating regulators’ ability to detect and investigate market abuse. In the crypto-asset market, a digital asset may be issued on multiple DLTs and traded or settled on multiple DLT market infrastructures. The identifiers used in traditional markets do not alone enable public authorities to identify the specific DLT on which a digital asset was issued, traded or settled. However, the DTI, as an identifier designed to cater to the specific features of the crypto-asset market, can identify the specific DLT on which a token was issued or where a transaction took place: it provides the link between the digital asset and the DLT.
For example, an ISIN would be allocated to a traditional bond. A DTI could be allocated if the bond was tokenised and represented as a token on a distributed ledger, or if the bond was natively issued on a distributed ledger. The ISIN provides a unique reference to the security, while a DTI provides a unique reference to the security token.
Additionally, DTIs could be allocated to non-financial instrument tokens such as crypto-assets or asset-referenced tokens (commonly referred to as stablecoins).
Example: ISIN-DTI Issuance – EIB Bond
In April 2021, EIB issued a digital bond on a public chain (link to press release). DTIF issued DTI WGHBLG826 for this bond, bringing together the following elements:
- Asset identifier, ISIN: FR0014003521
- Ledger, DLI: 9DDKPFN21 (Ethereum)
DTIF machine-readable reference data allows market participants and regulators to:
- Map digital tokens to the Asset
- Map digital tokens to the DLT
See the DTI Implementation guideline on the DTIF webpage.
See also: DTI Factsheet →