Prayer: Forgetting Qunut
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1107
If a person intentionally does not perform qunūt, it cannot be made up. If he forgets to perform it and remembers it before bending forward to the extent required for rukūʿ, it is recommended that he stand up and perform it. If he remembers it in rukūʿ, it is recommended that he make it up after the rukūʿ. If he remembers it in sajdah, it is recommended that he make it up after the salām.