Tenn. Code Ann. § 45-16-102

An agreement to share electronic terminals or participate in a shared electronic network shall not prohibit, limit, or restrict the right of a financial institution to charge a usage fee for use of its electronic terminals, require a financial institution to limit or waive its rights or obligations under this section, or require the financial institution to otherwise distinguish or discriminate on classes or types of transactions. This section shall not limit or restrict any other fee that a financial institution may impose on its customers pursuant to any deposit, lending, or other written agreement that it has with a customer, or to any other transaction where a customer has no written agreement, but which a customer has notice of the fee.