One Kaddish for Two Deceased When Hired for This Purpose

If someone is hired by two different people to say Kaddish for their relatives, does he need to dedicate a Kaddish for each deceased, or can one Kaddish be said for both?

It is preferable to dedicate a Kaddish for each deceased individually. If this is not possible, it is permissible to be lenient and consider that one Kaddish can suffice for two different people.

This is what the poskim have written, and it is not similar to what the Ba'er Heitev wrote in Siman 132 in the name of Knesset Yechezkel, and similarly in Kitzur Shulchan Aruch Siman 26, paragraph 16, that if someone is in mourning for both his father and mother, one remembrance suffices for both, since his father and mother brought him into the world, and the merit in saying Kaddish is that their offspring causes sanctification, unlike when saying Kaddish for people who are not his descendants, one Kaddish is less effective for two people. However, in times of need and great expense, it is permissible to be lenient and consider one Kaddish for two people. The person saying Kaddish should inform them.