The first time you swap or add liquidity, you have to approve the token to be swapped. This gives the Uniswap Protocol permission to swap that token from your wallet.
The approval transaction allows the Uniswap Protocol permission to swap the token you granted approval for from your wallet. You have to complete an approval transaction for every token you want to swap using the Uniswap Protocol.
Here a guide on how to complete an approval transaction:
- Enter your swap details.
- Select “Confirm swap” after reviewing swap details.
- In your wallet app or wallet extension, approve the spending limit for the token you are swapping.
Your wallet may require you to enter the number of tokens you want to approve. Please enter a number that is greater than or equal to the amount of tokens you are swapping.
- In your wallet app or wallet extension, allow the token to be used for swapping. This transaction will require a network fee.
- In your wallet, confirm the swap.
- Once the swap is confirmed, the transaction is submitted to the blockchain (pending).
- You will see “Success” and a green checkmark on screen when the transaction is successfully completed.
This token approval lasts for 30 days. After 30 days, the token approval will expire and the token will have to be approved again.
However, this approval is completed with a signature request. An approval signature does not require a network fee.