What is a sweep account, and how does it work? Sweep accounts allow you to set a balance limit and have any additional funds automatically "swept" into your other accounts. For example, Wells Fargo's Cash Sweep account has a default Money Market Fund Sweep that moves your excess funds to an MMF. So, choosing the right sweep account involves a little more work than opening a regular checking account. With sweep accounts, it's important to keep an eye on all the accounts your money is disbursed to.