An estate tax return is the formal filing-commonly IRS Form 706-used to report a decedent's taxable estate, claim deductions and credits, and calculate federal estate tax due. It lists assets at date-of-death value, debts, administration expenses, prior taxable gifts, and elections such as portability of the deceased spousal unused exclusion (DSUE). Large or complex estates may require appraisals and supplemental schedules. The return is generally due nine months after death, with extensions available. Accurate preparation coordinates with wills, trusts, beneficiary designations, and liquidity planning to ensure taxes are paid without forced sales of illiquid assets.

Advisors coordinate with estate counsel and CPAs to prepare Form 706, gather appraisals for closely held businesses, and size life insurance for liquidity. They review portability elections, charitable bequests, and apportionment clauses so beneficiaries aren't surprised by tax burdens. Timely filing and funding prevent fire-sale asset dispositions and keep the estate on schedule for settlement.