I did use TurboTax and my Federal tax due for last year was automatically imported when Federal penalty was calculated. NJ instruction says installment interest "may be" charged if my total tax is more $400 and I didn't pay at least 80%. I met both criteria. Note that I'm NOT talking about penalty. I'm talking about interest on underpayment (line 52 of NJ 1040). If required, I'd like to pay sooner rather than later as the interest rate is very high and compounds quickly. Is interest assessed starting from 1/15/23 when estimated payment was due? Or as long as I pay tax due prior to 4/18/23, I don't owe any interest?
