The L$ Balance and the US$ Balance

I asked one of the helpers here, but I wanted an official answer.

It is my understanding that form this page
https://secondlife.com/currency/

I can sell lindens in my account and increase my US$ Amount on account with SL

My Main Question about this is here:

Can/Will this US$ Amount be used (first) to pay the $9.99 a month Premium Fee and any land charges before SL dips into my CC?

Mainly I would like to keep enough in the US$ balance so I don't have to worry about any CC problems

Thanks

Yes, it will be used first. More info on this page.

Cheers,
Lawrence