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Encyclopedia Ethereum · Entry 123

Soulbound tokens: transfer restrictions and issuer powers

AI-assisted research · separate automated verificationCorrections

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Ethereum
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2 cited records
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In this article

At a glance

Key facts

Key facts for Soulbound tokens: transfer restrictions and issuer powers
FactDetailSource
Signallocked(tokenId) reports whether the specified token is locked.[1]
Transfer ruleERC-721 functions that transfer the token between accounts must fail while it is locked.[1]
ScopeThe standard is a minimal extension, not a universal credential policy.[1]
01

A token can represent an issuer’s assertion

A project might use a non-transferable token to represent course completion or membership. The contract can restrict transfer, but the value of the assertion still depends on who issued it and how eligibility was checked.

A blockchain account is not automatically one person. Preventing the token’s transfer does not prove exclusive control of the account’s signing authority.

02

Ask about revocation and account loss separately

Different implementations may add expiration, burning, revocation or migration policies. The minimal locked interface does not make these policies uniform.

A reader evaluating a credential should identify what happens after a mistake, a compromised key or the issuer’s closure. The “soulbound” label is not a recovery plan.

03

Non-transferability does not make a public claim private

If a token and its ownership are publicly inspectable, others can associate the credential with that account. Metadata may disclose additional information.

Evaluate what is published and whether the subject consented to that disclosure. Transfer restrictions and privacy are different properties.

Direct answers

Questions people ask

Does a soulbound token prove that an account belongs to one unique human?

No. The transfer restriction alone does not establish uniqueness, identity or the process used to issue the claim. Those require separate evidence and mechanisms.

Inspect the evidence

The answer and key facts have stable claim links. These records retain the scope and qualification when reused.

“Soulbound token” commonly describes a token designed to be non-transferable. ERC-5192 provides a minimal interface for reporting whether an NFT is locked and requires transfers to fail while locked. It does not by itself prove a person’s identity or define a complete issuance, revocation, privacy or recovery system.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Signal: locked(tokenId) reports whether the specified token is locked.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Transfer rule: ERC-721 functions that transfer the token between accounts must fail while it is locked.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Scope: The standard is a minimal extension, not a universal credential policy.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Revision history
  1. — First publication after primary-source research and independent automated verification.

Source register

Sources and references

Retrieval dates and locators are recorded individually.
  1. Minimal Soulbound NFTsEthereum Improvement Proposals

    A minimal locked-token interface; not a universal identity or revocation design.

    Locator: Specification · Version / scope: EIP/ERC-5192; retrieved document hash recorded · Retrieved: 2026-10-02T17:03:42.322ZOpen source
  2. Non-Fungible Token StandardEthereum Improvement Proposals

    Optional token metadata interfaces and the distinction between token and external resource.

    Locator: Specification: ERC721Metadata; Metadata Choices (metadata extension); NFT Identifiers · Version / scope: EIP/ERC-721; retrieved document hash recorded · Retrieved: 2026-10-02T17:03:42.309ZOpen source
How this article was made

Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.

Editorial method and corrections

Degrees of Satoshi editorial project. “Soulbound tokens: transfer restrictions and issuer powers.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/soulbound-tokens/