I received a gift from my dad who is a citizen of a foreign country in 2019. I did a quick search back then and I realized I don't have to pay tax on it. Now I was told that I should have disclosed the gift even though it was not taxable. And when I disclose it in my 2020 taxes (as an amendment for my 2019) there will be a penalty.
Is that true? and if yes, how much will be the penalty?
Thank you so much for your professional help!