The Guyanese dollar (currency sign: $, G$ and GY$; ISO: GYD) has been the unit of account in Guyana (formerly British Guiana) since 29 January 1839.

When sterling began to depreciate in the early 1970s, a switch to a US dollar peg became increasingly attractive as an anti-inflationary measure and the Eastern Caribbean Currency Authority (of which Guyana was a member) made the switch in October 1975.

The aspects of that history that are peculiar to British Guiana are the continued use of the four pence groat coin when all other territories had abandoned it, and also the use of dollar accounts in both the public and private sectors since 1839.

In the other Eastern Caribbean territories, there was a mixture of dollar and sterling accounts until the year 1951.

The Dutch territories of Essequibo, Demerara, and Berbice on the north coast of South America, created in early 17th century, came under the control of the British during the Napoleonic wars.

Then in 1839, the Spanish dollar as a unit of account was introduced in order to facilitate the introduction of British sterling silver coinage.

The rationale behind this lies in the fact that Spanish silver dollars, alternatively known as pieces of eight, were already circulating alongside the Dutch coinage, and also widely throughout the Eastern Caribbean.

This was a direct consequence of its equivalence to the very popular outgoing 'bit' coin which was equal to one quarter of a guilder.

In 1955, the BWI$ was decimalized and coinage was issued in the name of the "British Caribbean Territories, Eastern Group".

The 100-dollar note is similar to the preceding issue of the same denomination, except the design has been slightly modified with larger numerals for the denomination in the upper left front corner, a different screen trap background pattern, and shortened printer imprint.

Both notes now have designs that extend to the borders and watermarks that include an electrotype map of Guyana.