In the theory of capital structure, internal financing or self-financing is using its profits or assets of a company or organization as a source of capital to fund a new project or investment. Internal sources of finance contrast with external sources of finance. The main difference between the two is that internal financing refers to the business generating funds from activities and assets that already exist in the company whereas external financing requires the involvement of a third party. Internal financing is generally thought to be less expensive for the firm than external financing because the firm does not have to incur transaction costs to obtain it, nor does it have to pay the taxes associated with paying dividends. Many economists debate whether the availability of internal financing is an important determinant of firm investment or not. A related controversy is whether the fact that internal financing is empirically correlated with investment implies firms are credit constrained and therefore depend on internal financing for investment.[1][2] Studies show that the availability of funds within a company is a major driver for investment decisions.[3] However, the success and growth of a company is almost entirely dependant on the financial management and the use of internal financing does not explicitly mean success or growth for the firm. The financial manager can use a range of sources including but not limited to retained earnings, the sale of assets, and the reduction and control of working capital to drive expansion and better utilise funds. The availability of internal finance does not have a massive effect on firm growth.[4]