I think what you're getting at DavidMoses is, how should we split up the cost of taxes. I think really, in order to do that (assuming relatively equal earnings and expenses) you're going to need to look at how much tax you owe together as a couple, divide that by your individual proportions of your joint income, and subtract your individual tax prepayments. Depending on your individual tax situation that might not lead to a fair distribution of tax costs.
