Filing and paying taxes by the due date is important and you can avoid interest and penalty.

Personal Income Tax	Due Date
Individual Income Tax Return is due by	15-Apr
Individual income tax payment is due by	15-Apr
U.S. citizens or U.S. residents (includes Green card holders or other U.S. tax residents) residing outside the United States	15-June
Non-resident Alien who was not employed in the United Sates	15-June
Non-resident with employment income from the United States	15-Apr

How to request IRS for an automatic extension of time to file your U.S. individual income tax return?.

You can pay all or part of your estimated income tax due and indicate that the payment is for an extension using Direct Pay on the Electronic Federal Tax Payment System, or using a credit or debit card.
You can file Form 4868 (Individual) 7004 (Corporate) electronically by accessing IRS e-file, using your tax software or by using a tax professional who uses e-file.
You can file a paper Form 4868/7004 and enclose payment of your estimate of tax due.

Note: This is a one time request for a particular tax year and maximum allowed extension of time for a tax year.

Corporate Income Tax	Due Date
U.S. Corporation Income Tax Return 1120 for a C-Corporation	The 15th day of the 4th month after the corporation’s tax year-end.
U.S. Corporation Income Tax Return 1120S for an S-Corporation	The 15th day of the 3rd month after the corporation’s tax year-end.
Extension accepted by IRS –	An additional 6 months.
Estimated tax payments –	Payments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the corporation’s tax year.

Note: a corporation with a fiscal tax year ending June 30th must file by the 15th day of the 3rd month after the end of its tax year In this case if you apply for an extension, you can get 7 months extension instead of 6 months. A corporation with a short tax year ending anytime in June will be treated as if the short year ended on June 30, and must file by the 15th day of the 3rd month after the end of its tax year.

Employer’s Responsibility	Due Date
Report the Annual FUTA tax on wages on Form 940	The last day of the first calendar month after the calendar year ends.
Report your QUARTERLY social security and Medicare taxes and withheld income taxes on wages on Form 941	The last day of the first calendar month after the calendar quarter ends.
Certain small employers – report the ANNUAL social security and Medicare taxes and withheld income tax on Form 944	The last day of the first calendar month after the calendar year ends.
Report the Annual income tax withheld on all nonpayroll items on Form 945	The last day of the first calendar month after the calendar year ends.
Forms W-2, W-2AS, W-2CM, W-2GU, W-2VI, W-3, and W-3SS are due by	31st-Jan

Note: Most quarterly and annual filing due dates are the same date of the month as the monthly due date, but there are some exceptions. Many States give you a discount for timely filing and payment.

SALES AND USE TAX MONTHLY FILER	Due Date
California	30th of the following month
Florida	19th of the following month
Kansas	25th of the following month
Maine	15th of the following month
Montana	No Sales and Use Tax
Nevada	30th of the following month
New Mexico	25th of the following month
North Dakota	30th of the following month
Ohio	23rd of the following month
Oregon	No Sales and Use Tax
Utah	30th of the following month
Washington	25th of the following month
Wisconsin	30th of the following month
Wyoming	30th of the following month
Rest of the States	20th of the following month

Note: Most quarterly and annual filing due dates are the same date of the month as the monthly due date, but there are some exceptions. Many States give you a discount for timely filing and payment.