It should become obvious. Assuming you become profitable, eventually you will have cash left over at the end of the month, and nothing else important to do with it other than to pay yourselves.
There are some technical issues here. You haven`t mentioned exactly how you are organized. Are you a partnership, a corporation, or an LLC?
The organization type determines whether you receive wages subject to payroll withholding and receive dividends (corporations), or whether you just take distributions from your share of profits (partnerships). Partnership distributions are NOT subject to payroll withholding, partnership earnings are considered self-employment income.
LLC`s can elect to be taxed as a partnership or as a corporation, and that election determines the nature of the payments made to the owners. Salaries paid to corporate shareholders are deductible to a corporation. Payments to partners are normally NOT deductible to a partnership (exceptions do apply).
Your partnership agreement probably should spell out how and when distributions are made. Actual profits rarely equal cash in the bank, so you and your partner are going to need to agree on how much of what`s in the bank is actually available to be paid out to you. Otherwise, you might decide to pay yourself, and not leave enough cash available to pay your partner. Not nice ...
Personally, I don`t see the point of two signatures. I mean if you don`t trust each other now, and don`t believe that each partner will act in the best interest of the partnership, then how do you expect the partnership to succeed?
R Scott Reynolds, CPA