In the abscence of any official agreement it is assumed that all partners have an equal stake in the partnership. However, there can be situations when you wish to alter this. A classic example is when one person is the "leading light" and the other partners are merely "ancillaries" to the venture. In such circumstances you may wish to alter the shareholding so that one partner has a greater % share and the other partner a lesser share. The decision really is between the partners to decide what best fits the requirements of the venture.