Allocating space for sub-domain Cpanel accounts

[seriocomic]

Ok, some of my domains allow for sub-domains that have their own cpanels.

e.g. www.thissite.com has it's own cpanel but it's subdomain not.thissite.com also has a cpanel.

My question is, when setting up the main site (www.thissite.com) in WHM, do I have to allow for all the subdomains, email accounts, and space those subdomains will be later allocated in their own acounts?

Or is the quota allocated to the subdomain seperate from the main domain?

I ask this because when I set up say the main account in WHM, and then later the subdomain cpanel account in WHM, the sub-domain quota is additional to the main domain quota.

Does this make sense??

M.