The Deadline to file corporate tax returns (forms 1120, 1120A, and 1120S) is Thursday March 15th. Most corporate returns are required to be filed electronically therefore they must be sent to the IRS before midnight on the 15th. If for some reason you are filing a paper corporate tax return, the post mark on the envelope must show 11:59pm or earlier in order to avoid late filing penalties.
If you require more time to file your corporate return, you can request a 6-month extension by filing Form 7004, however this too much be electronically filed by the March 15th Deadline.
Lastly, the the March 15th deadline to claim a refund also applies to amended corporate tax returns (Form 1120X) for tax year 2008. If you require assistance with any of the above, contact an R&G Brenner professional before the deadline so that we can offer immediate assistance.