Can I apply for a Wildcard Certificate for each sub-domain of the main domain?

Yes, but it can be simpler and more cost effective to open an account as an Enterprise Public Key Infrastructure Manager (EPKI Manager). For more information, contact sales@comodoca.com.

It may also be more cost effective to use a Wildcard Certificate that protects all sub-domains below the primary named domain. For more information, contact sales@comodoca.com