Hawzah News Agency – Q: A junub person fasts for some days without knowing that being free from janābah is required for a valid fast. Do they have to pay kaffārah for the days fasted in the state of janābah, or it is enough to perform the qaḍā’ of those fasts?

A: In the given case, it is enough to perform their qaḍā’.

Source: https://www.leader.ir/en/book/32/Practical-Laws-of-Islam