A C-Corp pays income tax by filing a tax return with the IRS using Form 1120 – U.S. Corporation Income Tax Return, and an S-Corp using Form 1120S – U.S. Income Tax Return for an S Corporation.
The deadline to file an extension Form 7004 for 1120 and 1120-S is 15th day of the 3rd month after the end of the tax year of the return. For example, if the close of your business tax year is December 31, 2018, your completed form must be received by the IRS by March 15, 2019.
1120 and 1120-S returns, both gives you a 6 months extension of time to file your tax returns. Meaning 1120 & 1120-S will extend your filing deadline to September 15.
However, these forms may be complicated and can consume a lengthy process, with less time in hand to E-file Form 7004 for Tax Year 2018, the best way to get it done on time without facing the hazels of Interests & Penalties is by E-filing your Federal Extension Tax Form 7004 through www.Extensiontax.com an IRS Authorized E-file Service Provider for E-filing Federal Extension Tax Forms & Excise Tax Forms.
Do remember that filing an Extension only gives you more time to prepare and file your tax form. IT DOES NOT PROLONG THE TIME TO PAY YOUR TAXES. Business Income Taxes you owe has to be paid on the actual due date, which is March 15, 2019.
Every minute you delay thinking about your choices, is taking you close to penalties and Interests. Log on to www.Extensiontax.com right away and E-file your Form 7004 now. For any queries you may have feel free to reach our Tax Experts @ 1-866-245-3918 or you may even write to them @ support@extensiontax.com.
“Its tax time again, Americans: time to gather up those receipts, get out those tax forms, sharpen up that pencil, and stab yourself in the aorta” – Dave Barry. 
“This is the season of the year when we discover that we owe most of our success to Uncle Sam” – The Wall Street Journal