My tax return says that owe a tax penalty and interest. Why when I haven't filed it yet and the deadline has not passed?

[Ashby]

You probably owe the underpayment penalty. If you have tax liability over $1,000, it is likely that you will receive an underpayment penalty. The tax system is supposed to be "pay-as-you-go", so if you have untaxed income you are supposed to make estimated payments throughout the year or get the penalty.