The East African Community implements a common currency called the East African shilling

 
The shilling was the currency issued for use in British controlled areas in East Africa from 1921 until 1969.[1] It was produced by the East African Currency Board. It is also the proposed name for a common currency that the East African Community plans to introduce.
 
History
 First East African shilling
The East African shilling was introduced to Kenya, Tanganyika (now mainland Tanzania), and Uganda in 1921, replacing the short-lived florin at a rate of 2 shillings = 1 florin. The short lived Florin had been a result of the rising price of silver which occurred in the wake of the first world war. At that time, the Indian Rupee was the currency of the British East African states. The Rupee, being a silver coin rose in value against sterling. When it reached the value of two shillings, the authorities decided to replace it with the Florin. From the florin thence came the East African shilling. The currency remained pegged to one shilling sterling and was subdivided into 100 cents.[2][3][4] In 1936, Zanzibar joined the currency board, and the Zanzibari rupee was replaced at a rate of 1.5 East African shillings = 1 Zanzibari rupee.[3] It was replaced by local currencies (Kenyan shilling, Ugandan shilling and Tanzanian shilingi) following the colonies' independence.[2][3][4]
In 1951, the East African shilling replaced the Indian Rupee in the Aden colony and protectorate, which became the South Arabian Federation in 1963. In 1965, the East African Currency Board was breaking up, and the South Arabian dinar replaced the shilling in the South Arabian Federation at a rate of 20 shillings to 1 dinar.[1][5]
The shilling was also used in parts of what is now Somalia, Ethiopia and Eritrea when they were under British control. Before 1941, these areas, then known as Italian East Africa were using the Italian East African lira. In 1941, as a result of World War II, Britain regained control and introduced the shilling, at a rate of 1 shilling to 24 lira. Italian Somaliland was returned to Italy in 1949 as a UN Trusteeship and soon switched to the Italian Somaliland somalo, which was at par with the shilling. British Somaliland gained independence in 1960, and joined what had been Italian Somaliland to create Somalia. Somalia used the Somali shilling which was at par with the East African shilling, with the East African shilling losing legal tender status in 1961.[6] Ethiopia regained independence in 1941, with British support and began using the East African shilling. Maria Theresa Thalers, Indian rupees, and Egyptian pound were also legal tender at the beginning of this time, and it is unclear exactly when this status ended. Full sovereignty was restored in late 1944, and the Ethiopian birr was reintroduced in 1945 at a rate of 1 birr = 2 shillings.[7] Eritrea was captured from the Italians in 1941, and began using the East African shilling, as well as the Egyptian pound, with the lira demonetized in 1942. When Eritrea formed a federation with Ethiopia in 1952, the birr, which was already in use in Ethiopia, was adopted in Eritrea.[8]
For a wider history surrounding currency in the region, see The History of British Currency in the Middle East.
 Second East African shilling
A new version of the currency is proposed by the East African Community, which consists of Kenya, Tanzania, Uganda, Rwanda, and Burundi. It may coincide with the creation of a constitution and an East African Federation between the member states in early 2010.[9]
 Coins
In 1921, holed, bronze 5 and 10 cents and silver 50 cents and 1 shilling coins were introduced. Holed, bronze 1 cent coins followed in 1922. Silver was replaced by cupro-nickel in 1948. The last coins struck in the name of East Africa were produced in 1964, by which time the colonies had gained independence.
 Banknotes
In 1921, notes were issued by the East African Currency Board in denominations of 5, 10, 20, 100, 200, 1,000 and 10,000 shillings, with the notes of 20 shillings and above also carrying the denominations given in pounds Sterling (£1, £5, £10, £50 and £500). In 1943, 1 shilling notes were issued, the only occasion that such notes were produced. 1,000 shilling notes were only issued until 1933, with 10,000 shillings notes last issued in 1947. The remaining denominations were issued until 1964.
http://en.wikipedia.org/wiki/East_African_shilling