Sajda Sahu in Nafl

Q: Is Sajda Sahu (prostration for a mistake in Salaah) for all Salaah like Nafl, etc or only for Fard?

A: Sajda sahu must be made in all prayers if a mistake occurs that warrants sajda sahu; in nafl, sunnat and faradh salaah.

Mufti Siraj Desai