I just received corrected 1099-R and 5498 forms for 2018. I amended the return online and now I owe money. The VA state website says "if your amended return results in additional tax due, interest must be paid on the tax you owe from the due date to the date filed or postmarked." Is this true and how do I calculate that? Does this apply to the Federal return as well since I owe for that amended return?
I would hope that I wouldn't need to pay interest since I just received the corrected forms which I had no control over.