The company may issue a portion of its authorised capital as and when it requires capital. The capital may be issued to the promoters, public or to specified investors. The portion of authorised capital that has been issued to investors is called issued capital.
The capital may be issued by the company either at its face value or at a premium (higher than the face value). In special cases shares may be issued at a discount (lower than the face value).
When investors subscribe to the capital issued by a company, they may be required to pay the entire price at the time of issue or in tranches (instalments). The portion of the issued capital that has been fully paid-up by the shareholders is the paid-up capital of the company.
Outstanding shares refer to the total number of shares issued by the company to its investors (including retail and institutions).
Paid up capital is always less than or equal to issued capital; Issued capital is always less than or equal to authorised capital, Authorised capital is the maximum amount that can be issued or paid up.