I am trying to avoid an underpayment penalty. In 2024 I am not on track to pay, 90% of current year taxes due to some investment income. However, I am on track to pay 110% of last year's taxes. The thing is, last year my taxes were materially lower due to an investment tax credit for solar panel installation. Am I allowed to count that tax credit in measuring last year's taxes for safe harbor qualification purposes? Or do I need to back out the credit first? If I can't count the credit, I probably would not be on track to pay 110% of last year's taxes, and would need to make an estimated payment to avoid penalty.
