A sweep transfer is a type of automatic transfer of funds between two accounts, typically a checking account and a higher-yield investment account, such as a money market fund or money market deposit account. The transfer occurs when the balance in the checking account exceeds or falls below a certain threshold limit, which is set by the account holder. The excess funds are then "swept" into the higher-yield account, where they can earn more interest than in the checking account. Sweep accounts can also work the other way around, moving funds from an investment account to a checking account when the owners balance falls below a set threshold. Sweep transfers are often used to maximize the return on idle cash and to provide a ready source of cash for investing. Sweep accounts can be set up for personal or business use, and they can be internal (within the same institution) or external (between different institutions) . Sweep transfers are initiated automatically, making them a hassle-free way to manage funds and prevent overdrafts.