topic I am filing for a 2018 extension. If I have underpaid my estimated taxes by $1100. Is there a penalty. If so, what is it? in Get your taxes done using TurboTax https://ttlc.intuit.com/community/taxes/discussion/i-am-filing-for-a-2018-extension-if-i-have-underpaid-my-estimated-taxes-by-1100-is-there-a-penalty/01/507587#M208056 Wed, 05 Jun 2019 02:22:15 GMT rnmurdock 2019-06-05T02:22:15Z I am filing for a 2018 extension. If I have underpaid my estimated taxes by $1100. Is there a penalty. If so, what is it? https://ttlc.intuit.com/community/taxes/discussion/i-am-filing-for-a-2018-extension-if-i-have-underpaid-my-estimated-taxes-by-1100-is-there-a-penalty/01/507587#M208056 Wed, 05 Jun 2019 02:22:15 GMT https://ttlc.intuit.com/community/taxes/discussion/i-am-filing-for-a-2018-extension-if-i-have-underpaid-my-estimated-taxes-by-1100-is-there-a-penalty/01/507587#M208056 rnmurdock 2019-06-05T02:22:15Z It would be roughly $40 https://ttlc.intuit.com/community/taxes/discussion/it-would-be-roughly-40/01/507593#M208061 <P>It would be roughly $40</P> Wed, 05 Jun 2019 02:22:16 GMT https://ttlc.intuit.com/community/taxes/discussion/it-would-be-roughly-40/01/507593#M208061 Ashby 2019-06-05T02:22:16Z