The initial authorized capital of the Bank was 250 million Units of Account (UA). Since then, the capital has undergone a series of special capital increases, a voluntary capital increase and six general capital increases.
The capital stock of the Bank is composed of paid-up and callable capital. The paid-up capital is the amount of capital payable over a period determined by the Board of Governors' resolution approving the relevant Capital Increase. The Bank's callable capital is subject to payment as and when required by the Bank to meet its obligations on borrowing of funds for inclusion in its ordinary capital resources or guarantees chargeable to such resources. This acts as protection for holders of bonds and guarantees issued by the Bank in the unlikely event that it is not able to meet its financial obligations.
In the event of a call, pro-rata payment must be made by member countries in gold, convertible currency or in the currency required to discharge the obligation of the Bank for which the call was made. There has never been a call on the callable capital of the Bank.
The latest general capital increase - Sixth General Capital Increase (GCI-VI) - was approved by the Board of Governors of the Bank on 27 May 2010 and became effective immediately. The GCI-VI increased the authorised capital of the Bank from 2,394,746 shares to 6,768,746 shares with a par value of UA 10,000 per share. The regional members hold 60% of the total stock of the Bank and non-regional members, the balance of 40%. The GCI-VI shares, a total of 4,374,000 shares, are divided into paid-up and callable shares in proportion of 6% paid-up and 94% callable.
Similar to GCI-VI, GCI-V shares were divided into paid-up and callable shares in the proportion of 6% paid-up and 94% callable while the proportion under GCI-IV was 12.5% paid-up and 87.5% callable.
Prior to the Sixth General Capital Increase (GCI-VI), the Board of Governors authorized two capital increases to allow the Republic of Turkey and the Grand Duchy of Luxembourg to become members of the Bank, subject to completion of the formalities specified in the Agreement establishing the Bank and in the General Rules Governing Admission of Non-Regional Countries to Membership of the Bank. On 29 October 2013, the Republic Turkey was formally admitted as the 78th member country of the Bank and Luxembourg became the 79th member country in May 2014.
Similarly, in May 2012, the Board of Governors authorized a Special Capital Increase of the authorized share capital of the Bank to allow the Republic of South Sudan to become a member of Bank. In April 2015, South Sudan completed its membership process and became the 80th member country of the Bank and the 54th regional member country.