ISO 22739:2020 is the foundational International Organisation for Standardisation standard that establishes a comprehensive vocabulary of terms and definitions for distributed ledger technology (DLT) and blockchain systems, providing a normative reference for terminology used across all subsequent blockchain-related ISO standards, regulatory documents, and technical specifications. The standard was developed by ISO/TC 307 (Blockchain and distributed ledger technologies) and covers over 60 core concepts including blockchain, distributed ledger, smart contract, consensus mechanism, node, fork, digital asset, cryptographic key, and wallet.
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- ISO/TC 307 was established in 2016 in response to the rapid growth of blockchain technology and the proliferation of inconsistent, vendor-defined terminology that hampered regulatory clarity, procurement, and technical communication. Australia, which held the secretariat, led a 32-country working group through a multi-year drafting process. ISO 22739 was published in June 2020, with subsequent corrigenda. The standard’s methodology follows ISO/IEC Directives Part 1 for terminology standards: each term is given a preferred label, a normative definition, and where necessary a note clarifying scope or distinguishing related terms. The standard is technology-neutral, applying equally to permissioned and permissionless DLT systems.
- The scope of ISO 22739 covers the foundational layer of blockchain terminology. Key clusters of definitions include: network and topology terms (distributed ledger, blockchain, node, peer-to-peer network, consortium), data structure terms (block, genesis block, chain, transaction, hash, Merkle tree), protocol terms (consensus mechanism, proof of work, proof of stake, fork, finality), identity and access terms (digital identity, cryptographic key, wallet, address), and application terms (smart contract, token, digital asset, decentralised application). The definitions are deliberately precise: for instance, a “blockchain” is defined as “distributed ledger with confirmed blocks organised in an append-only, sequential chain using cryptographic links,” distinguishing it from distributed ledgers without the chained-block structure.
- The practical importance of ISO 22739 extends beyond technical standardisation into regulatory and legal domains. Multiple national regulators — including the Financial Conduct Authority (UK), the European Banking Authority, and financial regulators in Singapore, Japan, and Australia — cite or align with ISO 22739 definitions in policy documents addressing blockchain-based financial instruments. The EU’s MiCA (Markets in Crypto-Assets) regulation, which came into force in 2024, employs terminology substantially consistent with ISO 22739 definitions, enabling cross-border regulatory harmonisation. The standard also informs legal contract drafting for blockchain-based commercial transactions, where precise definition of “smart contract,” “execution,” and “finality” has legal consequences.
- By 2024-2025, ISO 22739 is in its second edition review cycle, driven by the need to incorporate terminology for Layer 2 networks, cross-chain protocols, zero-knowledge proof systems, and decentralised finance constructs that had limited representation in the 2020 edition. ISO/TC 307 has published or is developing over 30 standards and technical reports referencing ISO 22739 as their normative vocabulary foundation. The standard has been adopted nationally by ANSI (United States), BSI (United Kingdom), DIN (Germany), and standards bodies in over 50 countries. It represents the international consensus on how blockchain concepts should be precisely named and bounded, a prerequisite for coherent global governance of blockchain technology.