If you e-filed Form 4868, check the acknowledgment or confirmation supplied by your software or preparer. If you requested an extension by making an eligible IRS payment, select the extension payment reason and retain its confirmation number; you do not need a separate Form 4868. For a mailed application, keep the form copy and mailing evidence. Do not assume a missing transcript entry proves the application failed.
An extension gives more time to file, not more time to pay. For most individual filers, a timely six-month extension runs to October 15. Overseas, military and disaster provisions can change the applicable deadlines; check the relief that actually covers you.
Primary sources
Get an extension to file your tax return | Internal Revenue Service