Updated October 18, 2026. Quick answer: Part III is where a married couple consents to treat their gifts to third parties as made one-half by each spouse. You complete it only if you checked Yes on line 19 of Part I. A married couple may not file a joint gift tax return, so each spouse files separately and the consenting spouse signs a Notice of Consent.
When to complete Part III
The instructions say “Complete this part only if you checked” Yes on line 19 of Part I. They add “A married couple may not file a joint gift tax return.” The deeper rules on splitting are on the gift splitting page, and the return as a whole is on the Form 709 page.
Lines 1 to 3: the consent and the spouse
Line 1 asks “Do you consent to have the gifts” made by you and your spouse to third parties during the calendar year considered as made one-half by each of you. The instructions say “check the “Yes” box on line 1, and complete lines 2 through 7.”
Line 2 is “Name of consenting spouse” and line 3 is “SSN of consenting spouse”.
Lines 4 and 5: marital status
For line 4: “If you were married to one another for all of 2025, check the” Yes box and skip to line 6. “If you were married for only part of the year, check the “No” box and go to line 5.”
For line 5: “Check the box that explains the change in your marital status during the year and give the date you were married, divorced, or widowed.” A warning follows: “If you were divorced or widowed after you made the gift, you cannot elect to split gifts if you remarried before the end of 2025.”
Line 6: whether your spouse files
The form’s caption for line 6 reads “Will a gift tax return for this year be filed by your spouse?” and adds “If “Yes,” mail both returns in the same envelope”. The instructions say “you should file both of your individual gift tax returns together to help the IRS process the returns”.
Line 7: the Notice of Consent
The instructions say “Your spouse (the consenting spouse) must sign the Notice of Consent” for the election to be valid. “The Notice of Consent must be signed and dated by the consenting spouse” The required statement is described as “a statement signifying consent to treat all gifts made to third parties as having been made onehalf by each spouse”.
On timing: “The Notice of Consent may generally be signed at any time after the end of the calendar year.” There are two exceptions. “The consent may not be signified after April 15 following the end of the year in which the gift was made.” The instructions continue: “But if neither you nor your spouse has filed a gift tax return for the year on or before that date, the consent must be made on the first gift tax return for the year filed by either of you.” The second exception: “The consent may not be obtained after a notice of deficiency for the gift tax for the year has been sent to either you or your spouse.”
“The executor for a deceased spouse or the guardian for a legally incompetent spouse may indicate the consent.”
What the consent covers
The instructions say “The consent is effective for the entire calendar year” and “If the consent is effective, the liability for the entire gift tax of each spouse is joint and several.” The requirements start with “You and your spouse were married to one another at the time of the gift.”
Where the number comes from
Part III has no dollar amounts to compute. The entries come from your marriage and divorce records, your spouse’s Social Security number, and the signed Notice of Consent. If one spouse made all the gifts, the instructions say “then only one Notice of Consent is required”.
Where it goes next
Part III feeds the split-gift columns on Schedule A. Schedule A column (h) reads “For split gifts, enter 1/2 of column (g)”. The totals reach the tax computation in Part II lines 1 to 12.
Edition and line numbers
This page reads Form 709 (2025) and the 2025 Instructions for Form 709. Those are the current files irs.gov served on 2026-10-18, byte-identical to the archived copies. The instructions state “For gifts made during calendar year 2025”. Check the year printed on your own Form 709 and use the line numbers on that year’s form.
Common mistakes
- Treating the return as joint. The instructions say “A married couple may not file a joint gift tax return.”
- Letting the consent go past its deadline. The instructions say “The consent may not be signified after April 15 following the end of the year in which the gift was made.” If neither spouse has filed by then: “the consent must be made on the first gift tax return for the year filed by either of you.”
- Splitting after remarrying. The instructions say “you cannot elect to split gifts if you remarried before the end of 2025.”
Related: Form 709, gift splitting, Form 709 due date and extension, and Form 709 and the annual exclusion.
Sources
- Instructions for Form 709 (2025), United States Gift (and Generation-Skipping Transfer) Tax Return, for gifts made during calendar year 2025: https://www.irs.gov/pub/irs-pdf/i709.pdf
- Form 709 (2025), United States Gift (and Generation-Skipping Transfer) Tax Return: https://www.irs.gov/pub/irs-pdf/f709.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.