What is T-REX (ERC-3643)?
T-REX (ERC-3643) is an Ethereum token standard for compliant, permissioned security tokens. It enforces on-chain identity and transfer rules so that only verified, eligible wallets can hold or trade a tokenized security — embedding KYC and eligibility checks into the token itself.
Also called: ERC-3643 · T-REX standard · permissioned security token · compliant token standard
How T-REX works
Each holder has an on-chain identity (ONCHAINID) carrying verified claims — identity, jurisdiction, accreditation. The token's compliance module checks the applicable rules on every transfer (eligibility, jurisdiction limits, lockups) and blocks any transfer that would break them. Compliance is enforced by the token contract rather than left to an off-chain gatekeeper, so the rule travels with the asset instead of ending at a platform's edge.
The standard is built from four moving parts: the token itself, an identity registry mapping wallets to identities, a set of trusted claim issuers, and a compliance module holding the transfer rules. An issuer can update the rules — adding a jurisdiction, extending a lockup — without reissuing the token, which is what makes a permissioned standard workable over a security's life.
What it does and does not solve
T-REX gives an issuer enforceable transfer control, a recoverable position if a holder loses keys, and a register that a transfer agent can stand behind. What it costs is composability: a permissioned token cannot sit in a permissionless pool, cannot be sent to an unverified wallet, and cannot move to a chain where its identity registry does not exist. That trade is the point, not a defect — but it is the reason a regulated security token does not behave like a crypto asset.
Frequently asked questions
What is the difference between ERC-20 and ERC-3643?
ERC-20 tokens are freely transferable to any address. ERC-3643 (T-REX) adds mandatory on-chain identity and transfer-restriction logic so a token can only move between verified, eligible wallets — the requirement for regulated security tokens.
Can an ERC-3643 token be traded on a normal DEX?
Generally no. A permissionless pool cannot hold a token whose contract requires both sides of every transfer to carry valid identity claims, so trading happens on venues that are themselves onboarded into the registry.
Where this shows up live
On the desk
Methodology — what we do and do not claim
Every figure on those pages carries its source and as-of time. Nothing is shown when the upstream is unavailable.
Read the desk note
The longer version, written from the desk: The laws and pipes tokenization actually runs on.
Related terms
- ONCHAINID — ONCHAINID is the on-chain identity layer used by permissioned security-token standards such as T-REX (ERC-3643).
- KYC / AML Gate — A KYC/AML gate is the check that decides which wallets may hold or receive a regulated token.
- Transfer Agent — A transfer agent is the regulated record-keeper of who owns a security.
- Tokenized Equity — A tokenized equity is a blockchain token that represents ownership of, or economic exposure to, a real company share.
More in Compliance
Attestation · Eligibility (US vs Non-US) · KYC / AML Gate · ONCHAINID · Proof of Reserve · Transfer Agent
Informational only · not financial advice. See the live numbers on the data desk, the sourcing rules in the methodology, or the day's stories in the newsroom. · ← All glossary terms