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Wallets & safetyStart here·4 min read

Revoke an ERC-20 Approval

Revoking an allowance changes the token contract’s permission state. It is its own on-chain transaction, so it requires wallet approval and network gas.

Key idea

Identify the spender first. Revoking the wrong allowance can break an app you still use without reducing the permission you meant to remove.

In this guide

  1. 01Find the live allowance
  2. 02Confirm the spender
  3. 03Approve the revoke transaction

Related workflow

Token Approvals →
01

Find the live allowance

Review current permissions rather than only recent transactions. An approval created months ago can still be active today.

02

Confirm the spender

Match the spender address to the protocol or contract you intend to revoke. Names and logos are not enough for a security-sensitive action.

03

Approve the revoke transaction

A revoke changes on-chain state and therefore costs gas. Review the network, token and spender again in your wallet before signing.

Concept map · schematic

How a token allowance is used

Authorization and spending happen in separate transactions.

  1. 01

    Owner

    Controls the ERC-20 tokens and grants permission

  2. 02

    Allowance

    Token contract records a spender and maximum value

  3. 03

    Spender

    May transfer tokens within the remaining allowance

Important: An approval is not a swap. A permission can remain after the associated trade.

Live, read-only fieldwork

Read a live token allowance

Ask the token contract how much one spender can transfer from one public account.

Inspect one on-chain ERC-20 allowance

Choose a network and supply public addresses. This is one token–owner–spender relationship, not a wallet-wide approvals audit. No wallet connection or signing required.

Source: existing Hexncoin EVM RPC relay using read-only eth_call. The reading does not detect ERC-721 approvals, permits, or other spender/token pairs. A contract may not implement the standard ERC-20 interface correctly.

These examples read public network or indexer data only. You cannot execute trades, approve permissions, or submit transactions here.

Primary references

Documentation and standards

References added

Official technical references for further verification. A source link is not a guarantee that every earlier editorial sentence has been reverified; provider specifications may also change over time.

Originally published 2026-09-13 · Guide text last updated 2026-09-19 · Reference links and live examples updated 2026-10-24

  • ERC-20 token and allowance specificationEthereum Improvement ProposalsRead source ↗

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