In an effort to reduce the risk inherent to transaction processing and allow for lower merchant rates, a certain percentage of your monthly credit card earnings are temporarily held until the end of the month, at which point, or upon closure of the merchant account, they are deposited into your bank account. This money is held so that, in the event of a chargeback, it is available to repay the customer.

This process is called a Rolling Reserve, continues indefinitely, and is based on the risk-level of the merchant.