Note that you cannot e-file your tax extension request for certain tax forms â including Form 8612, 8613, 8725, 8831, 8876, or 706-GS(D). To get an extension for these forms, you must mail a paper tax extension request (Form 7004) to the IRS.Itâs also important to remember that Tax Form 7004 does not extend the time for payment of any tax due, only the time for filing a return.f you chose to e-file Tax Form 7004 through the FileLater system and your request is rejected for any reason, you may make corrections and resubmit your tax extension at no extra charge.