Zakah is obligatory on paper currency.
Machine translationRead the Arabic original
The Shaykh : Paper currency is also subject to zakah because it is a substitute for dirhams and dinars, and a substitute carries the ruling of the thing it replaces.
If a person possesses paper currency equal to the nisab of silver, it is obligatory for him to pay its zakah, which is one-quarter of one-tenth.
If a person possesses paper currency equal to the nisab of silver, it is obligatory for him to pay its zakah, which is one-quarter of one-tenth.