What is Mail Float?

Mail float is the time required for a check payment to travel from the payer to the payee through the postal system. The duration of this mail float will cost the recipient interest income, since the funds have not yet arrived, and so cannot be invested.

Payers may be highly cognizant of the amount of mail float generated when they mail check payments to their suppliers. Payers can use this information to cut checks for which they do not yet have available funds, or to keep the required funds parked in a high-yielding investment instrument for a few extra days. They can increase the mail float duration by mailing checks to customers from distant locations that require more transit time to reach customers.