# Pre Phase

The `pre` phase is executed after the `prepare` phase, and is used for checking if explicit conditions hold before executing the remainder of the transaction. A common example would be checking requisite balances before transferring tokens between accounts.

```
pre {
    sendingAccount.balance > 0
}
```

If the `pre` phase throws an error, or does not return `true` the remainder of the transaction is not executed and it will be completely reverted.