Your perogative. See below for the two opinions.
Both parents deceased:<a href="#_ftn1" name="_ftnref1">[1]</a> One is to light a Yizkar candle for his deceased father and mother. [This implies that one is to light a single candle on behalf of both parents.<a href="#_ftn2" name="_ftnref2">[2]</a> Some Poskim<a href="#_ftn3" name="_ftnref3">[3]</a>, however, rule that if both one’s father and mother are deceased, one is to light two candles in their memory.]
<a href="#_ftnref1" name="_ftn1">[1]</a> See Admur 610:5; Rama 610:4
<a href="#_ftnref2" name="_ftn2">[2]</a> Elya Raba 610:4
<a href="#_ftnref3" name="_ftn3">[3]</a> Elya Raba 610:4; Bigdei Yesha; Kaf Hachaim 610:28; Nitei Gavriel 75:12

Shulchan Aruch HaRav | How many Yizkor candles should one light? One for each parent, or a single candle suffices?

Your perogative. See below for the two opinions. Both parents deceased:[1] One is to light a Yizkar candle for his deceased father and mother. Some Poskim[3], however, rule that if both one’s father and mother