# AA31 paymaster deposit too low

`AA31 paymaster deposit too low` is an ERC-4337 EntryPoint error that means the paymaster's deposit in the EntryPoint is too low to cover the user operation's required prefund.

:::info
The first 20 bytes of the `paymasterAndData` field specify the address of the paymaster contract you are requesting to use.
:::

The paymaster contract does not have enough funds deposited into the EntryPoint contract to cover the required prefund of the user operation.

## Possible solutions

* Verify that the `paymasterAndData` field is correct, and that the first 20 bytes are the address of the paymaster contract you intend to use.
* If you are using your own paymaster contract, deposit more funds into the EntryPoint contract through the `deposit()` function of the paymaster contract.
* If you are using a paymaster service like Pimlico, [reach out to them](https://t.me/pimlicoHQ).