Why not just send in an estimated tax payment with (at same time as) each draw? IRS won't mind getting more payments more often. No one has to remember when to send in. Dad won't be afraid kid will spend it or you're embezzling or whatever his concern is. It'll feel more like w/h from payroll to those who have been asking for payroll. I had one client I gave a bunch of blank ES coupons to, well, amounts were blank, her info was on the rest; she's a headhunter and liked to pay her taxes from each fee she receives. Had trouble getting her to do at least four and at least on the due dates, but some years she did many more. She was happy and did record when and amounts for me.