By default when you set up a fee it is applied directly to the merchant and paid to your referrer Available Balance. Another fee customization is the ability to configure the entity liable for a specific fee. By setting up Fee Modifiers you can change who is paying the fee. As an example, if you have a fee that you want to charge to one client based on the activity of another account, such as if they were linked businesses, you can set up a fee modifier so that when one merchant triggers a fee the funds are taken from a different merchant entity.