Doubting whether one performed 4 or 5 rakaats

Q:

1. If I am praying 4 rakah salah and in the last rakah I doubted whether I prayed 4 or 5 rakah... as there is no 5 rakahs so I base myself on 4 rakahs and complete my prayer without doing sajda e sahw...is my prayer is valid?

2. Do I have to do sajda e sahw in this situation?

A:

1. Yes.

2. No.

And Allah Ta'ala (الله تعالى) knows best.

Answered by:

Mufti Ebrahim Salejee (Isipingo Beach)