Source : Reliable Fatwas / 23 Apr 2014

Question : When should the Masbooq stand to perform his missed raka’ts – after the Imaam’s first or second Salaam?

Answer : The masbooq should stand up just as the Imaam is about to make the second Salaam. It is not necessary to wait for the completion of the second Salaam. The rule in this regard is that the Masbooq should stand when he realizes that there is no Sajdah Sahw. Thus when the Imaam begins to make the second Salaam, he will understand that there will be no Sajdah Sahw. However, another valid view is to stand after the Imaam’s second Salaam.