How to revoke token allowances

tl;dr: BlockWallet lets you remove token access from any of the DApps you’ve used in the past.

What are token allowances?

When using a decentralized application (DApp) that involves your ERC-20 token holdings, you'll likely need to approve its access to the smart contract for that token. For example, if you want to swap token A for token B, the DApp will need your permission to withdraw token A from your wallet, before sending the necessary amount of token B to your wallet.

Token allowances are specific to one token, meaning that if you've granted an allowance for a DApp to access your USDT, it will only have access to that token.

Having pre-approved access to a number of tokens can save time, as it eliminates the need to grant permission for every new transaction. This feature makes web3 activities more efficient and convenient. With that being said, there are possible downsides to having such convenience.

Why should I revoke token allowances?

Granting token allowances is a standard part of web3, and issuing approvals is generally not problematic. However, DApps can be vulnerable to exploits and hacking attempts, and having an unlimited token allowance can put your funds at risk. If a DApp's code has a vulnerability, it may be possible for bad actors to exploit it and order the DApp to withdraw your funds without your consent.

Additionally, it's possible that the site requesting the token approval is malicious. This can happen if you visit a site that looks like a trustworthy site or brand, but is actually designed to steal your tokens.

Always research any site to which you grant token allowances, as sometimes, a DApp deployed by a bad actor can steal your funds as soon as you click 'approve' on the token.

How to revoke token allowances on BlockWallet

BlockWallet allows you to have control over your token allowances, and to protect yourself from potential scam attack vectors.

Here are the following steps on how to customize your token allowances:

1. Navigate to Settings - Account - Token Allowances
   1. Search for the allowance you wish to revoke by token (ex. USDT, DAI, USDC…) or spender (ex. 1Inch, LiFi, Uniswap…)
   2. You can also group allowances by spender or token to revoke a specific group of allowances.
2. Click Revoke next to the allowance you wish to revoke.
3. Confirm the allowance transaction which resets token allowance to zero (0).

For those looking to revoke all of their token allowances quickly, use Revoke All. This option consecutively revokes all token allowances in your wallet, eliminating the need to revisit the Allowance page for each action.