20 Rupees 70th Anniversary of the Central Bank of Sri Lanka

The Central Bank of Sri Lanka was established in 1950 under the Monetary Law Act, making it one of the earlier independent central banks in post-colonial South Asia. Its founding came just two years after Ceylon's independence, and the institution was built substantially on technical assistance from the Federal Reserve and the IMF during the initial years of operation.

Nickel plated steel rather than a cupro-nickel alloy reflects the broader regional shift toward cheaper base-metal coinage that accelerated through the 2010s as metal costs climbed.