This depends on the gravity of that sin and when you had made it. When seeking Allah’s forgiveness, it is not only the du’a or the two Rakah that erases the sins. It is the remorse and humility one constantly displays.

My question is as follows… Is reciting Sayyidul Istighfar at fajr and maghrib daily enough for me to repent from my sins? Or do I have to pray two rak’as and then supplicate to Allah for forgiveness?

Sins | November 16, 2015 4:56 am
Previous

Shaikh, I masturbated and promised Allah that I will not do it again. I broke my promise and did it again and promised him that I will not do it. This went on. Then I fasted 3 days for breaking my promises. But after that, I masturbated again. Then, I asked Allah to forgive me. But this time, I did not promise Allah that I will not do it again. Do I need to fast 3 days again
Next

if somebody is doing something haram because I encouraged them to do it, but since then I have repented, if the other person still continues to do the wrong thing, will I still be sinful for it even though I have repented?