How to Safely Approve and Revoke Token Allowances
What a token approval actually grants, and why periodically reviewing and revoking them matters.
Jump to section
What to remember
- A token approval grants a contract permission to move a specific token from your wallet.
- Unlimited approvals are convenient but carry real risk if the approved contract is later compromised.
- Periodically reviewing and revoking unused approvals is a practical security habit.
- Approvals don't expire on their own — old, forgotten ones remain active indefinitely.
What a token approval is
A token approval grants a specific smart contract permission to move a certain amount (sometimes unlimited) of a token from your wallet, generally required before interacting with a DeFi protocol so it can execute swaps or deposits on your behalf.
Why unlimited approvals carry real risk
Many interfaces request an unlimited approval by default, for convenience across future transactions. If that specific contract is later compromised or found to be malicious, an unlimited approval could let an attacker move far more than any single transaction actually required.
Practical steps
- Where an interface allows it, approve only the specific amount a transaction actually needs, rather than an unlimited amount.
- Periodically review your wallet's active approvals using a dedicated token-approval-checking tool.
- Revoke approvals for contracts or protocols you no longer actively use.
An old, forgotten approval is a real, ongoing exposure
An approval doesn't expire on its own — a contract you approved months or years ago, and have since forgotten about, still holds exactly the permission you originally granted it.
What to remember
- A token approval grants a contract permission to move a specific token from your wallet.
- Unlimited approvals are convenient but carry real risk if the approved contract is later compromised.
- Periodically reviewing and revoking unused approvals is a practical security habit.
- Approvals don't expire on their own — old, forgotten ones remain active indefinitely.
Related concepts
The Wallet-Drainer and Approval-Phishing Economy: How It Actually Works
Read the research article
What to Do Immediately After Signing a Malicious Approval
Read the full guide
Residual Risk After Revoking a Token Approval
Read the article
Protecting Against SIM Swap Attacks
Read the full guide
How to Set Up a Multi-Signature Wallet
Read the full guide
What Is a Crypto Airdrop?
Read the full guide
What to Do If You've Been Scammed in Crypto
Read the full guide
Ice Phishing
Read the Ice Phishing glossary definition
How Wallet Drainers Work: Blind Signing and Malicious Permit Signatures
Read the article