When you use a decentralised finance app, you usually grant it a token approval — permission for its smart contract to move a certain amount of your tokens on your behalf. This is a normal part of how decentralised exchanges and lending platforms work, but approvals often outlive their usefulness. Months later, a contract you barely remember may still hold permission to move your tokens, and if that contract is ever exploited, your funds are at risk even though you have not used the app in ages. Some wallets now warn you when an app requests an unlimited approval, giving you a chance to edit the amount before confirming — a feature worth enabling if your wallet offers it.

Approvals are often granted for unlimited amounts by default, which is convenient but risky. An unlimited approval means the contract could, in theory, move your entire balance of that token. Many experienced users prefer to approve only the exact amount needed for a single transaction, accepting the small extra cost of approving again later. The trade-off is worth understanding: convenience today versus exposure tomorrow. Approvals on less-used networks are easy to forget, so check every network you have ever used, not just the main one, since stale permissions can linger on side chains for years.

Reviewing your approvals is straightforward with reputable approval-management tools that connect to your wallet in read-only fashion. These tools list every contract holding permission over your tokens, the amounts approved, and when the approval was granted. Work through the list and flag anything surprising: contracts for apps you no longer use, approvals for tokens you no longer hold, and any unlimited approvals on tokens with significant balances. When revoking, remember that each revocation is itself a transaction that needs network fees, so batching the work and choosing a low-congestion moment can save a noticeable amount.

Before revoking, double-check that you are using a legitimate tool and that you are on the correct network, because approval tools themselves are sometimes impersonated by phishing sites. Only connect your wallet through the official website or app, never through a link in an email or direct message. Revoking itself is a blockchain transaction, so it costs a small network fee — another reason to batch your cleanup into one session rather than revoking one approval at a time across many days. A useful habit is to revoke approvals immediately after finishing with a one-off app, rather than letting them accumulate until a periodic cleanup becomes a large chore.

When you revoke, prioritise ruthlessly. Start with unlimited approvals on valuable tokens held by contracts you no longer use, then move to approvals for apps you rarely touch. Keep approvals only for apps you actively use and trust, and consider reducing unlimited approvals to exact amounts where the tool allows it. After revoking, verify the change took effect before moving on — a failed transaction leaves the approval in place. Some approval tools also show a risk score for each contract, which can help you prioritise, though you should still verify surprising entries yourself rather than trusting any single score.

Make approval hygiene a routine, not a one-off panic. A monthly check takes only a few minutes and prevents the slow accumulation of stale permissions that creates risk over time. Pair it with a habit of approving exact amounts for new apps, and of disconnecting your wallet from sites after use. These small disciplines compound into a much stronger security posture without any cost to your daily trading. If you find an approval you do not recognise at all, treat it as a warning sign: investigate how it appeared before assuming it is harmless, since unexplained approvals deserve caution.

Think of token approvals like keys you have handed out: every app you have ever used may still hold one. Periodically collecting those keys back is basic crypto housekeeping, and it is one of the highest-value security habits a DeFi user can build. The few minutes it takes could be the difference between an exploited contract being someone else's problem and it becoming yours. Over time, approval hygiene becomes second nature, and the few minutes it takes each month buy a level of protection that is disproportionate to the effort involved.