On June 16, 2026, the Connecticut Supreme Court unanimously rewrote the playbook for estate tax domicile disputes. In Daniels v. Commissioner of Revenue Services, SC 21150, the Court held that an estate challenging the Department of Revenue Services’ (“DRS”) residency determination in Connecticut Superior Court need only prove domicile by a “preponderance of the evidence”—the ordinary civil standard—rather than the far more demanding “clear and convincing evidence” standard that had been assumed to be the standard for over two decades. The Court’s ruling sent a $13.2 million estate tax assessment back to Connecticut Superior Court for a new trial and handed multi-state taxpayers a meaningful procedural advantage.
Link to Why This Case Matters Why This Case Matters
For years, the determination of domicile in Connecticut estate tax disputes has operated under the shadow of Leonard v. Commissioner of Revenue Services (264 Conn. 286, 2003), a sales and use tax case that required taxpayers to present “clear and convincing evidence” that an assessment was erroneous. Since 2003, both taxpayers and the DRS have reflexively applied that same high “clear and convincing” bar to all tax disputes, including estate tax domicile fights—even though the Supreme Court had never actually extended Leonard beyond sales and use tax appeals.
Link to The Fact Pattern The Fact Pattern
The decedent in Daniels was a retired health-insurance executive who maintained homes in Connecticut, Florida, and Arizona. From 2006 until his death in 2015, he spent roughly five and a half months per year in Connecticut (May through mid-October), three and a half months in Florida, and three months in Arizona. He filed a Florida domicile declaration in 2006, held a Florida driver’s license, registered to vote in Florida, and maintained a Florida bank account. But he also kept four cars registered in Connecticut, three in Florida, and maintained substantial personal and social ties in both states. The DRS applied its 28-factor regulatory test (Conn. State Agencies § 12-701(a)(1)-1(d)(8)), weighted the factors internally, and concluded the decedent died a Connecticut resident.
On appeal, the trial court concluded that the executor had failed to demonstrate, by clear and convincing evidence, that the decedent was not a Connecticut domiciliary at the time of his death. The Superior Court also noted that “at best, the evidence demonstrating that [the decedent] was a domiciliary of Florida at the time of his death [was] equivocal and well below the quantum of evidence necessary to convince [the] court that it was highly probable that [the decedent] was a Florida domiciliary at the time of his death and not a Connecticut domiciliary.”
Link to The Holding That Changed the Landscape The Holding That Changed the Landscape
The Supreme Court held that the determination of domiciliary status, for estate tax purposes, should be based on the “preponderance of the evidence” standard, and not the higher “clear and convincing evidence” standard. What makes the decision so unusual is that both parties to the case, as well as trial court, assumed that the executor had to present “clear and convincing” evidence of his domiciliary status. The question of what is the appropriate burden of proof in the case was actually first raised by the Supreme Court at oral arguments, and following the oral arguments, the Supreme Court ordered the parties to file supplemental briefs addressing whether the “clear and convincing” standard articulated in the Leonard decision should apply to the present case.
Under General Statutes § 12-391(h)(1), every decedent is presumed to have died a Connecticut resident, and the estate bears the burden of proving otherwise. The estate tax statutes are silent on the standard of proof. The Court noted that the general rule in Connecticut was that when a civil statute is silent, as is the case with estate tax appeals, the default is the lesser “preponderance of the evidence” standard. In addition to appeals in the sales and use tax area, the Court indicated that the higher “clear and convincing” standard is generally reserved for quasi-criminal wrongdoing, fraud, or cases touching fundamental personal rights. The Court concluded that an estate tax domicile determination is a fact-and-intent question, not the kind of extraordinary circumstance that demands extra deference to DRS. In holding that estate tax domicile cases should be determined based on the usual preponderance of the evidence standard, the Court remanded the case back to the trial court for a new trial using the “preponderance of the evidence” standard rather than the “clear and convincing evidence” standard.
Link to Practical Takeaways for Taxpayers and Advisers Currently Dealing with Estate Tax Domicile Audits Practical Takeaways for Taxpayers and Advisers Currently Dealing with Estate Tax Domicile Audits
The Court made it clear that its decision was limited to the proper burden of proof in Connecticut estate tax domiciliary determinations. The Court did not make determination as to whether the “preponderance of the evidence” standard should apply to any other issue that arose in an estate tax appeal. It also did not indicate whether or to what extent its holding should apply for purposes of determining the correct burden of proof for disputes involving other Connecticut taxes.
The case has an immediate and significant impact on any estate in which the issue of the decedent’s domicile is currently under audit by the DRS, or which is being appealed to the Appellate Division of the DRS. Any taxpayer or adviser that is involved in an estate tax domicile case should take a fresh look at the merits of the taxpayer’s position based on the newly minted “preponderance of the evidence” standard. It may well be that in light of the lesser burden of proof, a case that prior to Daniels was headed to litigation, may now be more susceptible to being resolved.
Link to The Broader Takeaway: Looking Ahead The Broader Takeaway: Looking Ahead
As a result of the Daniels decision, the clear and convincing standard set forth in Leonard is still operative for sales and use tax appeals. However, it is unclear how this decision will impact the DRS’ internal policy and future court decisions on determining the burden of proof in other tax appeals.
Of particular interest, will be whether the logic and analysis of Daniels will be similarly applied to personal income tax disputes involving a determination of residency. It would seem as if many of the reasons used by the Court in holding that an estate tax domicile case should be resolved using the preponderance of the evidence standard should equally apply to personal income tax domicile cases. The question of the proper burden of proof in tax disputes other than sales and use tax or estate tax domicile cases may be resolved, in the short term, on a case-by-case basis. Ultimately, the issue may require a legislative fix.
The Daniels decision is a win for procedural fairness, and it arrives at an important time. Connecticut’s estate tax remains one of the steepest in the nation, and the state’s aging population of affluent retirees with ties to warmer climates makes estate tax domicile disputes a frequent battleground. The Daniels decision will help to level the playing field in connection with reaching an appropriate resolution to such disputes.
This post is for informational purposes only and does not constitute legal or tax advice. Consult qualified counsel regarding your specific situation.