So I have six children and because I get $2k per child I am getting $12k this year. Last year when I did my taxes I overpaid by $2k and with one less child I got about $9K between Fed/State. This year it shows I underpaid by about $2k but because of the $12K my refund is about $10K.

My question is do I keep raising my W4 exemptions until I get close to no refund (and if so, will I get in trouble because my underpayment will keep going up or the fact that I am not allowed to just willy-nilly increase it) or should I just get my taxes withdrawn so I end up paying exactly what I should and just take the $12K refund?

My W4 exemptions last year was 7 when I overpaid by $2k (with 5 children) and end of last year we had our sixth child and didn't change it until early January this year. I increased it to 8, then 9, and finally 11 thinking my checks will get bigger (about $40 over two weeks with the 9 though I don't know what my 11 exemption will be yet since I just updated it a few weeks ago)

I am already underpaying with an exemption of 7 at this point so I can drop it down to 5 and not owe anything in taxes and get the $12K or sit tight with 11 or keep increasing it. What is the right thing to do?