Payment Processing Frequently Asked Questions Contact Us Email: email@example.com Call: 800-878-4100 Welcome to Greylock Processing’s FAQ page, where you’ll find answers to commonly asked questions about payment processing. If you don’t find what you’re looking for, please feel free to contact us! What is a merchant account? How do I open a merchant account? Is there a contract term if I open a merchant account? What is a merchant discount rate? What is Interchange? What is a chargeback? How can I prevent chargebacks? What will my rate be every month? How do I calculate my effective rate? What is PCI compliance? How often is proof of PCI compliance requested? What is EMV? What is the best way to accept a credit card to get the lowest rate Why does American Express cost more money?