Some institutions purchase WebAssign for their students. If your institution is one of these, your students will not be billed.
If your institution does not pay for WebAssign, students must purchase an access code to use WebAssign.
If you have questions about billing for your institution, contact your Cengage representative. You can find your representative at cengage.com/repfinder/ https://www.cengage.com/repfinder/postSecondaryEdFacultyCanada/ https://www.cengageasia.com/Contact-Us http://www.cengage.co.in/Rep_Locator https://www.cengage.co.uk/education/contact-us-2/ https://au.cengage.com/repfinder/ https://latinoamerica.cengage.com/contacto/ (Latin America) or https://www.cengage.com.br/contato/ (Brazil).
You can check your section's Billing and Resources settings to see if students will be billed.