we can't see your return. there are multiple ways that your taxes can be calculated and the tax tables won't work if for example, you have qualifying dividends or net long-term gains. this would likely be the case if the tax tables are showing a higher tax than what Turbotax calculated. from what I've seen threads about tax calculation errors and responses it's the taxpayer that doesn't understand all the rules and methods. and that penalty could have been due to inaccurate entries by the taxpayer. if Turbotax made an error that cost you penalties and interest file a claim.
