How to Revoke Token Approvals and Protect Your Wallet

Every time you interact with a DeFi protocol, a swap, or a marketplace, you are asked to approve a token for spending. That approval tells the smart contract: “You may spend up to X amount of this token from my wallet.” If the contract is malicious or compromised, that approval can be used to drain your balance without further permission.

This guide explains what token approvals are, why they are risky, and how to revoke them on Ethereum, Binance Smart Chain, and other EVM-compatible networks. Unlike guides focused on emergency recovery after a suspicious signature, this one covers routine maintenance—proactive steps to keep your wallet safe before anything goes wrong.

Token approvals are a standard feature of ERC-20 and BEP-20 tokens. When you approve a contract to spend a token, you give it permission to move that token from your address. The approval can be set to any amount, including “unlimited” (a very high number like 2^256-1).

Legitimate protocols use approvals to enable swaps, lending, or staking. But once an approval is given, it remains active until you revoke it or the contract is destroyed. This is why old approvals to abandoned or compromised contracts are a common attack vector.

Wallet drainers scan the blockchain for addresses with high-value or unlimited approvals to vulnerable contracts. If the contract behind the approval has a bug, a backdoor, or has been taken over, the attacker can call `transferFrom` and move your tokens.

Real-world examples:
- The 2023 approval drain on a popular DEX aggregator that had a compromised front-end.
- Phishing sites that request a fake approval and then use it to empty wallets.
- Unused approvals to test contracts or deprecated protocols that no longer have active security monitoring.

You can check your approvals using block explorers or dedicated dashboard tools.

Go to Etherscan Token Approval Checker.
Enter your wallet address.
The tool lists all token contracts you have approved, the spender address, and the approved amount.
You can filter by “Unlimited” to see the most dangerous approvals.

The same tool works on BscScan Token Approval Checker for Binance Smart Chain.

Most EVM chain explorers have a similar feature. For example:
- PolygonScan: polygonscan.com/tokenapprovalchecker
- Arbitrum: arbiscan.io/tokenapprovalchecker
- Avalanche C-Chain: snowtrace.io/tokenapprovalchecker

Revoking an approval means setting the approved amount to zero. You can do this directly from the block explorer or using a dedicated revoke tool.

Open the token approval checker page for your address.
Locate the approval you want to revoke.
Click “Revoke” next to that approval.
Your wallet will ask you to sign a transaction that sets the allowance to 0.
Confirm the transaction and pay the gas fee.

Revoke.cash is a popular third-party tool that aggregates approvals across multiple chains. Steps:

Visit revoke.cash and connect your wallet.
The dashboard shows all active approvals.
Select the approvals you want to revoke and click “Revoke selected.”
Sign the transactions.

Caution: Always verify the domain. Phishing sites have imitated revoke.cash. Bookmark the real URL.

Some users prefer to manually call the `approve` function on the token contract, setting the spender address to the contract and the amount to 0. This requires using the “Write Contract” tab on the token’s explorer page. Only do this if you are comfortable with smart contract interaction.

• Limit approval amounts. Approve only the amount you need for a single transaction, not unlimited. Many protocols now support “permit” signatures that expire.
• Use a dedicated burner wallet for test interactions and low-trust dApps.
• Audit your approvals monthly. Set a calendar reminder to review and revoke unused approvals.
• Check contracts before approving. Use source code verification on the explorer. If the contract is not verified, treat it as high risk.
• Beware of phishing sites that mimic legitimate dApps and request a token approval. Always verify the URL and the contract address.

If you notice that a token approval has been used by an attacker, move your remaining assets from that wallet to a new address immediately. Use a hardware wallet or a new software wallet. Do not attempt to “revoke” the approval from the same wallet if the attacker already has a transaction pending – they may be able to front-run your revocation. After moving funds, you can safely revoke from the empty wallet.

Source-tracked CryptoRescue article.

• [ ] Visit your block explorer’s token approval checker and review your current approvals.
• [ ] Revoke any approvals to contracts you no longer use or trust.
• [ ] For future approvals, choose custom amounts and avoid unlimited allowances.
• [ ] If you are unsure about a specific contract, check its audit history on sources like CertiK or SlowMist.
• [ ] Set a recurring monthly reminder to audit your approvals.

By following these steps, you turn a reactive security measure into a proactive routine. Revoking unnecessary token approvals is one of the simplest ways to reduce your exposure to wallet drainers and smart contract exploits.