Can I e-file multiple C Corp Extensions??

Certainly you can file multiple extension requests for different C-corps.  The only restriction, however, is that each separate C-corp extension must be on its own extension request (you cannot combine them, per IRS rules).  Thus, if you have (4) C-corps, and they all need filing extensions, then you would need to make (4) separate extension requests.  This restriction is identical to individual taxpayers, each with their own separate Social Security Numbers.

In order to file a C-corp extension request, you have at least at least really good (2) options.

First, you can simply go to the following IRS.gov website, download Form 7004 (Application for Automatic Extension of Time to File), along with the instructions, print it, and fill out this short form manually.  Then you could drop it in the mail as soon as possible.

https://www.irs.gov/uac/about-form-7004

Second, if you have the TurboTax Business software installed on your own computer, you can complete Form 7004 directly through the program, and then e-file Form 7004 (without having to wait on the postal service).

Information on how to file Form 7004 in TurboTax Business is really very straightfoward.  Simply follow the TurboTax prompts and interview screens.  The screen-capture images found below this text answer will demonstrate for you how to get started, or to search for Form 7004; simply click the pictures to open.