Edit the reseller privileges
There is no concept of a "sub" reseller in cPanel, without custom modifications. There is only root, and one level of resellers. Resellers cannot have resellers "under" them. root is not considered to be a reseller.
That said, you can allow a reseller to create accounts. This is specified in the WebHost Manager in
Main >> Resellers >> Reseller Center >> Edit reseller privileges & nameservers. The specific privilege is labeled
Create.
You may find our documentation helpful. The following section explains how resellers work in the cPanel environment:
Resellers