Q. I am (reciting) kaddish for a father of a female friend. He was niftar on the first day of Shavuos 5776 before sunset and buried on 8 Sivan. What would be the last day I would say kaddish? Thank you.

A. Kaddish is recited for only eleven months so as not to imply that one’s parent was an unrighteous person, since the guilty are judged for twelve months. (Remah – Shulchan Aruch Y. D. 376: 5).
In your case, when the first day of kaddish was Sivan 8, the last day to recite kaddish should have been eleven months later, on Iyar 7 (May 3), at mincha, so as not to begin month twelve. (begins at ma’ariv service).
Horav Shlomo Miller Shlit”a added that if someone is being remunerated for reciting kaddish, he may have to return some of the funds received. There are also different opinions in regards to saying it for a person that indeed qualifies as unrighteous.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a