the 2210 only computes underpayment of the estimated tax penalty. Turbotax does not compute the late payment penalty and interest. you can protest the penalty but you must have a reason that the IRS finds acceptable such as a disaster declaration for your area. in cases like this, where you are not really subject to them, the penalty and interest will be abated. if you have some other reasonable cause the IRS can abate penalties but not interest. As noted the balance due on your return should have been paid 4/15 with the application for extension or through the IRS website. Not 10/15. if you submit a request for abatement and the IRS rejects it, since payment will be even later additional penalties and interest would accrue. if you request abatement send the notice, the reason you believe the penalty/interest should be abated, and any payment to the address in the notice. You may not receive a response for months. use a tracking service so you know the IRS got it.
