January Jan-15 Make last 2019 estimated tax payment Jan-27 First day to e-file and first IRS acknowledgements of e-filed returns Jan-31 Deadline for employers to file Form W-2s with the Social Security Administration. Jan-31 Deadline for reporting payments to contract workers on Form 1099-MISC. February Feb-15 First day refunds issued for taxpayers claiming the Earned Income Tax Credit or the Additional Child Tax Credit. March Mar-15 Corporate Taxes due. April Apr-15 Last day to e-file returns and extensions Apr-15 First 2020 estimated tax payment due June Jun-15 Last day to e-file timely extension request for overseas taxpayers Jun-15 Second 2020 estimated tax payment due September Sep-15 Third 2020 estimated tax payment due October Oct-15 Last day to e-file returns that received 6-month extension