Jack Schitt Memorial Tower
Designated 'JS', it is located in the North-Eastern side of Corpclave. Corp HQs are here, they work much like apartments do.
Make sure you don't go trying random doors here, some will deliver a shock, get you stars within the building, and potentially get you killed by the security.
The cost of renting a corporate space at Jack Schitt is $50,000 up front, and $3,000 a month. These funds must be available in your corporate account.