What is an approval transaction?

The first time you swap or add liquidity, you have to approve the token. This gives the Uniswap Protocol permission to swap that token from your wallet.

Once you approve a token, you will not have to to approve that token again on the Uniswap web app. Each token from a specific wallet you wish to trade requires a one-time approval.

When swapping tokens on Uniswap Protocol, you will see the following message:


Once you select the Allow icon you can proceed to swap your tokens.

When you approve a token, it is considered a transaction so you will have to pay a network fee.