A question was asked in Torah Lishmah concerning someone who loses both parents in one year (R"L). Should the son recite Qaddish for both parents at the same time, or is it better for him to recite Qaddish for one of them and pay someone else to recite it for the other?
Hacham Yoseph Hayyim, 'a"h, replies that he is very hesitant to have someone else read the Qaddish when the son can do it. This is because the Qaddish of another has no value compared to that of the son's. I would like to add here, that in view of this, a son must take the obligation of reciting Qaddish for his parents very seriously and make every effort not to miss any.
In addition, he adds, if the son reads for only one parent, it would be an insult to the other parent who has been relegated to having the Qaddish read by someone else (whose Qaddish has much less value, no matter how important that person may be).
As such, he states, that the son should read for both parents. If he wishes to have someone else read for both of them also, he may, but there is no requirement for this.
(See Torah Lishmah, She-elah Taw Yod Beh)
