Fiat / issuer reservesRank #1
USDTTether USD
Tether Limited
- Market cap
- $184.6B
- Circulating supply
- 184.9B
- Networks
- 10
EIP/ERC standards & compliance
Full USDT profile: ERC-20, permit, proxy patterns, cross-chain, flash loans, and compliance EIPs — with implementation notes and verified contract context.
Overview
Largest stablecoin by market cap and dominant liquidity layer across crypto exchanges. Launched 2014 on Bitcoin Omni layer, now spans 15+ blockchains. Over $1T monthly volume.
Supply by chain
Market cap
$184.6B
Circulating supply
184.9B
Supply chains
127
| Chain | Supply | Market cap | Share |
|---|---|---|---|
| Tron | 87.8B | $87.6B | 47.5% |
| Ethereum | 78.9B | $78.8B | 42.7% |
| BSC | 9.2B | $9.2B | 5.0% |
| Solana | 2.7B | $2.7B | 1.4% |
| Arbitrum | 955.1M | $954M | 0.52% |
| Plasma | 920.3M | $919M | 0.50% |
| Polygon | 896.3M | $895M | 0.48% |
| Aptos | 826.2M | $825M | 0.45% |
| TON | 629.9M | $629M | 0.34% |
| Mantle | 394.0M | $393M | 0.21% |
| Avalanche | 372.1M | $372M | 0.20% |
| OP Mainnet | 197.4M | $197M | 0.11% |
| Other tracked chains (100) | 1.2B | $1.2B | 0.66% |
| Current circulating supply by chain from DeFiLlama. Small supply footprints are grouped after the top 12 chains and may include bridged or non-curated deployments. | |||
Features
Engineering-oriented breakdown of capabilities: standards, who they matter for, integration rationale, per-feature risks, and vetted external references (specs, docs, verified source).
Primary Ethereum verified source: Etherscan
| Feature | Standards | Audience | Why it matters | Risk / caveat | References |
|---|---|---|---|---|---|
Blacklist/Freeze compliance |
| Corporate | Integrations must assume `transfer` can revert for sanctioned or frozen addresses — design UIs and custody flows accordingly. | Censorship risk and sudden loss of spendability; not suitable for permissionless censorship resistance guarantees. | |
Cross-chain native via OFT cross chain |
| Both | USDT0 on L2s uses OFT for native burn/mint semantics — prefer OFT interfaces over legacy bridge-wrapped USDT when routing liquidity. | Misconfigured OFT peers or stale LayerZero endpoint IDs can strand or duplicate accounting across chains. | |
ERC-20 standard authorization | User | EVM integrations use standard `transfer`/`approve` plus Tether-specific admin hooks — treat as ERC-20 with extra revert cases. | Non-standard edge cases vs reference OpenZeppelin ERC-20; always test pause/blacklist paths. | ||
TRC-20 high-volume deployment compliance |
| User | Highest retail and CEX flow lives on TRON — integrations targeting fees/UX must support TRC-20 semantics and energy model. | Different address format and fee model vs EVM; operational mistakes lose funds. | |
Daily reserve transparency compliance | — | Corporate | Attestations underpin reserve narrative for compliance and listings — useful for off-chain risk monitoring, not on-chain proof of backing per se. | Attestation scope and methodology can change; not a substitute for your own risk policy. | |
Issuer mint/burn compliance |
| Corporate | Supply changes reflect issuer operations — indexers should track `Issue`/`Redeem` events where exposed, not assume fixed emission rules. | Supply shocks and operational errors originate off-chain; on-chain supply is authoritative for circulation only. |
EIP / ERC support matrix
Standards & compliance support for USDT. Click an EIP to jump to the global deep-dive section.
| Standard | Status | Notes |
|---|---|---|
| Core | ||
| ERC-20 Fungible token standard | Partial | Most liquid stablecoin but worst DeFi UX due to non-standard approve(). Every approve() call in a standard ERC-20 integration requires a two-step zero-first pattern for USDT, or the transaction reverts silently. |
| Signatures & typed data | ||
| EIP-712 Typed structured data signing | Not implemented | USDT cannot participate in any signature-based approval or transfer flow on Ethereum. Every DeFi interaction requires two on-chain transactions (approve + action). This is the single largest UX gap vs USDC for developers building payment applications. |
| EIP-2612 Permit — gasless ERC-20 approval | Not implemented | Cannot build gasless USDT flows without Permit2 as an intermediary or wrapping into a protocol-specific contract. |
| EIP-3009 transferWithAuthorization | Not implemented | USDT cannot be used in single-transaction payment flows. Protocols that build on EIP-3009 (like payment relayers and checkout flows) must either exclude USDT or require users to pre-approve. |
| EIP-1271 Signature validation for smart contracts | Not implemented | Smart-wallet permit flows are blocked upstream by USDT's lack of signature standards, not EIP-1271 specifically. |
| Upgradeability & proxies | ||
| EIP-1967 Standard proxy storage slots | Not implemented | Block explorers do not auto-detect USDT as a proxy. Etherscan shows the original 2017 ABI unless you manually find the current contract. Monitoring tools that watch standard EIP-1967 slots will miss USDT upgrades entirely. |
| EIP-1822 UUPS — universal upgradeable proxy | Not implemented | No UUPS considerations apply to USDT. The upgrade path is the custom deprecate() function documented in the EIP-1967 entry above. |
| Vaults & yield | ||
| ERC-4626 Tokenized yield vault standard | Not implemented | Use external protocols (Aave aUSDT, Compound cUSDT) for yield-bearing USDT positions. |
| Compliance | ||
| Freeze Address freezing / blacklisting | Implemented | Same integration consideration as USDC: check isBlackListed() before building payment flows. The single-owner model means blacklisting power cannot be delegated independently. |
| Seize Fund seizure / clawback | Implemented | Supply tracking tools MUST listen for DestroyedBlackFunds events — standard ERC-20 event monitoring will miss these supply changes. totalSupply() decreases when funds are seized. |
| Pause Global transfer pause | Implemented | Same risk model as USDC pause — all USDT-dependent DeFi would halt. The concentrated owner key means pause decisions are made by a single entity without multi-sig or timelock requirements. |
| Cross-chain | ||
| ERC-7802 Crosschain token interface | Partial | Network-specific: USDT0 / non-Ethereum deployments only; Ethereum uses an OAdapterUpgradeable lockbox for canonical USDT. For cross-chain USDT transfers, integrators should treat USDT0 as a deployment-specific extension path rather than assuming the canonical Ethereum USDT token itself implements ERC-7802. |
| Flash Loans | ||
| ERC-3156 Flash loans | Not implemented | Use external flash loan providers for single-transaction USDT borrowing. |
| Data sourced from verified Etherscan contract source code. Implementations may differ across networks — always verify on the specific chain you integrate with. | ||
Technical notes
- Ethereum USDT uses 6 decimals; BNB Chain USDT uses 18 decimals.
- Ethereum TetherToken (Solidity 0.4.x) is one of the most non-standard ERC-20s: transfer/transferFrom/approve return void (not bool) — requires SafeERC20.
- approve() reverts if allowance != 0 (use forceApprove).
- Dormant fee-on-transfer via basisPointsRate/maximumFee (currently 0/0, activatable by owner).
- destroyBlackFunds() burns blacklisted balances — more aggressive than USDC's freeze-in-place.
- USDT0 (Jan 2025) adopts LayerZero OFT + draft ERC-7802 crosschainMint/crosschainBurn across 15+ networks (OpenZeppelin audited, no critical findings, $50B+ moved).
- Custom deprecate() upgrade mechanism — NOT EIP-1967 standard proxy slots.
Reserves & peg
- Reserves
- Total reserves ~$191.8B (Q1 2026): US Treasuries ~$141B, gold ~$20B, Bitcoin ~$7B, plus cash & equivalents, repo, and money market funds. Excess reserves buffer ~$8.2B (figures shift each quarter)
- Collateral
- Fiat and equivalents (off-chain)
- Peg mechanism
- Hard 1:1 via centralized issuer redemption
- Auditor
- BDO Italia (quarterly attestation); KPMG engaged March 2026 for first full financial audit
Ecosystem
- DeFi integration
- Deep Uniswap, Curve, Aave, Compound liquidity across all chains
- Yield
- None native
Risk factors
mediumCentralizationmediumRegulatory exposurelowHistorical reserve opacity
Technical references
Networks & contracts
Deployments by chain — primary rows are highlighted. Always verify addresses against issuer docs before mainnet integrations.
| Network | Standard | Upgrade | Contract |
|---|---|---|---|
EthereumPrimary | ERC-20 | Custom | Largest supply chain, 13M+ holders |
TRONPrimary | TRC-20 | — | Highest tx volume, cheapest fees |
BNB ChainPrimary | BEP-20 | Immutable | |
SolanaPrimary | SPL | — | |
ArbitrumSecondary | ERC-20 | Transparent | USDT0 native L2 via LayerZero OFT |
PolygonSecondary | ERC-20 | ↕ Bridged via Polygon PoS bridge — separate deployment from Ethereum | |
AvalancheSecondary | ERC-20 | Transparent | |
OptimismSecondary | ERC-20 | Immutable | |
Bitcoin OmniSecondary | Omni | — | Historical deployment only — Tether no longer issues or redeems Omni USDT |
TONSecondary | Jetton | — |
Engineering deep dive
Integration notes
When routing USDT on EVM, assume pause and blacklist are live: design flows that fail gracefully if transfer reverts. For L2 USDT0, prefer the documented LayerZero OFT interfaces over legacy bridge wrappers.
Liquidity
USDT is the default quote asset on most CEXes and the deepest stable on blue-chip DEX pools—treat it as the baseline for slippage and oracle assumptions.