Overview
A Soulbound Token, or SBT, is a non-transferable cryptocurrency token that represents a person's identity, credentials, or reputation on a blockchain. Unlike regular NFTs, SBTs cannot be bought, sold, or transferred; they are bound to a single account, called a Soul. The concept was proposed to bring verifiable identity and social trust on-chain without making credentials tradeable.
How It Works
An issuer, such as a university, employer, or community, mints an SBT directly to a recipient's account. The token's non-transferability is enforced either at the protocol level or through social and community enforcement, since a token could technically be transferred by the holder. Because SBTs persist with the account, they can accumulate into a verifiable reputation history that applications can read when deciding trust or access.
Why It Matters
SBTs could enable credit scoring, sybil resistance, and verifiable credentials in Web3, addressing a major gap: blockchains are good at proving what you own but poor at proving who you are. Their challenges include privacy, revocation, and preventing a secondary market from forming. As of 2026 the concept remains experimental but influential across identity and reputation design.
Related Concepts
SBTs belong to the Identity layer alongside ENS and Account Abstraction. They interact with Governance by enabling identity-weighted voting and with DAO reputation systems that are not tradeable.