I'm a contractor, startup founder, and investor. I spend tons of time aggregating data to determine what tax I owe at the household level (I'm married and my wife works) so I can 1) make quarterly estimated payments, and 2) not have to worry about sourcing cash or paying penalties at tax return time.<p>I haven't found a good tool to help with or automate any of this and I'm thinking about building one.<p>Do you care about this problem? How do you solve it? What's it worth to you?
My tool --- compare to last years income/taxes and ratio appropriately.<p>It's all just a guess anyway. You can't make it exact unless you're psychic and know that next quarter will be a big one or a bad one.
I am not a professional accountant or CPA.<p>But from my experience as a self-employed (in the US), you are in “safe harbor” if you just plan to pay at least 90% of last year’s tax bill (spread throughout the year) and then estimate any additional taxes due in January prior to the April deadline based on end of year totals.<p>Again, it’s just a suggestion, so discuss this with your tax accountant.