What Form 7004 is for
irs.gov says to use Form 7004 to request an automatic 6-month extension of time to file certain business income tax, information and other returns. The instructions say the extension is granted if you complete the form properly, make a proper estimate of the tax (if applicable), file it by the due date of the return, and pay any tax that is due. Line 1 asks for the form code of the return the application is for; the form lists the codes. RepeatForm cannot tell you whether you need an extension or which code applies.