Here are a few key tax-related deadlines for individuals through the rest of 2017. JUNE 15: Pay second installment of 2017 estimated taxes, if applicable. SEPT. 15: Pay third installment of 2017 estimated taxes, if applicable. OCT. 16: File a 2016 income tax return and pay any tax, interest and penalties due, if an automatic six-month extension was filed. DEC. 31: Incur various expenses that potentially can be deducted on your 2017 tax return. Contact us for more information about the filing requirements and to ensure you’re meeting all applicable deadlines.