Asalaamualkum
Kindly advise if the following is correct / authentic.
1.Qaza salat of a dead person can be offered by someone else on his behalf either on payment basis or without payment. He must do Niyyat that he is offering salat on behalf of that person.
2.If a deceased has not performed Hajj, firstly, try to perform his Hajj-e-Badal for him personally, or send someone as a representative to do so. If he has any previous Zakah to be paid, do so immediately. If he has any Qada of Salat or Roza (Fasting) perform the Kaffarah for him.
Jazakamullah