Maybe I'm misunderstanding your situation, but it seems like the corporation is now a C-corporation.

If a Partnership is a shareholder of the corporation, that invalidates that S-election.  A S-corporation can not have a Partnership as a shareholder.

If that is your situation, your client really needs to talk to whoever is doing the corporate return.

If I'm misunderstanding your situation, please give additional details.

Thanks for the response.  The client owns the stock personally they just filled out the information sheet incorrectly with the name of another entity.