In relation to a company, when a share is issued, the person applying for it must pay to the company, in cash or equivalent value, the amount of its nominal value together with any premium required by the company. Shares are fully paid when the whole amount has been received by the company (or, exceptionally, when the shareholder has given an undertaking to pay the whole amount).
Shares may also be issued on the basis that only part of their price is to be paid at the outset with the remainder being required when called for by the company.