I know that the weekly threshold where you start to pay PRSI is 352euros per week. Then you are charged 4% on all your earnings when you earn above this level. However if over the year your average earnings are less than this say 320euros per week but some weeks you earn 400euros whereas other weeks you earn 300 euros per week. Your average pay is less than 352 euros per week but some weeks you are paying PRSI because on that particular week you have earned above the threshold. Surely that is unfair on workers whose hours are precarious but on average they are earning below the threshold PRSI rate.