The World Federation One Stop Fiqh

Ruling 1191

If after prayers one realises that he was in a state of doubt during his prayer – for example, he doubted whether he had performed two rakʿahs or three rakʿahs – and he assumed that he had performed three, but now he does not know whether his supposition was actually inclined towards performing three rakʿahs or if both possibilities appeared equal to him, it is not necessary for him to perform ṣalāt al-iḥtiyāṭ.