Form 709 is annual
The IRS instructions describe Form 709 as an annual return. Reportable gifts for one calendar year go on that year's Form 709, and the instructions caution not to file more than one Form 709 for the same calendar year.
General due-date rule
For gifts made in 2025, the IRS instructions generally set the deadline at April 15, 2026. If April 15 falls on a Saturday, Sunday, or legal holiday, the due date moves to the next business day under the IRS rule cited in the instructions.
Two extension paths
An extension of time to file a calendar-year federal income tax return automatically extends the 2025 federal gift tax return. If no income tax extension is being requested, the IRS says Form 8892 is used to request an automatic 6-month extension for Form 709 or Form 709-NA.
Payment is separate
The IRS instructions state that neither extension method extends the time to pay gift or GST tax. If tax may be due, do not treat a filing extension as payment relief.
Consider professional review
Professional review is worth considering when a deadline was missed, tax may be due, the return involves GST, or you are unsure whether a prior extension covered Form 709. Tax Paperwork does not match users with professionals.
Keep proof of timely mailing
Paper filing requires the taxpayer to sign, mail, and keep records. If using an IRS-designated private delivery service, use the carrier's written proof of mailing date. If using USPS services, keep the mailing receipt, tracking, and any delivery proof purchased.