The hryvnia replaced the karbovanets at 100,000 to 1 and became Ukraine's sole legal tender
Background
The National Bank of Ukraine records that the president issued a Decree On the currency reform in Ukraine on 25 August 1996.
Karbovanets were exchanged for hryvnias at a rate of 100,000 to 1 hryvnia.
Both currencies circulated in parallel from 2 to 16 September 1996.
The hryvnia became the only legal tender in Ukraine on 17 September 1996.
Banknotes of 1, 2, 5, 10, 20, 50 and 100 hryvnias entered circulation on 2 September 1996.
The National Bank of Ukraine is the country's central bank and sets its key policy rate.
In plain words
Karbovanets Ukrainian karbovanets — The currency that circulated in Ukraine before the hryvnia.