You have lots of rights, not so much because you are a 50 percent shareholder, but because you will be able to elect yourself a director, and they have big rights including rights of inspection and an accounting. Announce that you will be participating, that starting now you will all follow the rules, and if you get any "push-back" consult a business litigator.
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Attorney Doland is correct. You have right to demand an accounting, and inspect all corporation documents. You want to start by holding and emergency shareholders meeting with an agenda and specific motions that address all your concerns.
If you meet too much resistence you can petition the court to dissolve the corporation, which could cause your cousin to come to negotiation table and either 1) run the company correctly, or 2) by you out. A business attorney can assist you with resolving this matter.
Phillip M. Smith Jr.
Los Angeles Tax & Business Attorney
Licensed in the United States Tax Court
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I agree with the other two answers and add that the first step you should take is review the Corporation's by-laws to determine the requirement and time period on calling a shareholders meeting with the board of directors.
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