- 3rd quarter estimated tax payments due for the 2018 tax year (individuals and calendar-year corporations).
- Final deadline to file calendar year-end corporate tax returns for the year 2017 if an extension was requested (Forms 1120, 1120S).
- June 30 year-end C corporations corporate tax due. If applying for an extension, you will receive a seven-month extension (due April 15, 2019).
- Final deadline to file partnership tax returns (Form 1065) for the year 2017 if an extension was requested.