Your K-12 school district has purchased access to Cengage for its students, but when students create accounts and sign in at the main Cengage home page, they are told their trial access will expire and asked for payment.
Cause
If your K-12 students are prompted for payment, their accounts were created through the Cengage higher education portal.
Resolution
K-12 students must create accounts and enroll in courses at nglsync.cengage.com/register and sign in at nglsync.cengage.com.