how to get related account id when creating a contact from subpanel

I need to prepopulate the address from the account when creating a contact from the contact sub panel (from account detail view)

so far I can get my result if I simply edit the contact (having a related account) and when the address fields are empty.

But if the contact is brand new, I can’t find where to fetch the account_id…
it should be available since the account name is shown and the system will need to add the account-contact relationship… so the account_id is store somehow…

How can I get it?