Conn. Gen. Stat. § 12-401

(b) If the judge of probate finds with or without a hearing thereon, from the administration account or other evidence available to and satisfactory to him, including written consents by those to whom the tax has been charged, that the federal estate tax and Connecticut estate tax, if any, as finally determined, have been paid and that the ultimate burden of such tax or taxes has been borne by a party or parties in interest in a manner satisfactory to them, or to their legal representatives, as evidenced by the written consent of such persons or of their legal representatives, no proration of the federal estate tax or Connecticut estate tax shall be made unless specially requested by any party in interest.

(c) Upon receipt of the computation provided for in subsection (a), the probate judge shall make a determination of the proration of the federal estate tax, if any, in the manner provided by subsection (a), except that, if all parties affected by such proration or their legal representatives endorse upon such computation their approval thereof, no hearing need be held thereon, but such determination may be made ex parte.

Prior to proration act, burden of federal and state estate taxes was on estate as a whole and, in absence of direction otherwise in will, was payable out of residuary estate without reimbursement from beneficiaries of inter vivos transfers included in taxable estate. 124 C. 66. Cannot apply retroactively to impair vested rights. 136 C. 126. Cited. Id., 141. In the absence of a clear directive to the contrary, the proration statute governs the manner in which the burden of the federal and state estate taxes must be borne. 139 C. 285. Undertakes to determine upon whom the ultimate burden of estate taxes shall be placed; it is not a taxing statute; were it not for the statute, that burden would, unless the will otherwise directed, fall upon the residuary estate; a directive in a will that all estate taxes be paid from the residue is not a directive against the prorating of estate taxes among residuary gifts. 144 C. 134. Testator must clearly indicate there is to be no proration; marital deduction allowed against portion of residuum given to widow. 145 C. 542. In absence of clear direction that proration statutes should not apply to death taxes attributable to nontestamentary property, statutes are applicable and burden of taxes fell on recipients of that property and not on the estate. 149 C. 335. In case of doubt as to meaning, the tax burden will be left where the law places it. 165 C. 376. Surviving spouse's statutory share under Sec. 45a-436 must be calculated prior to the deduction of any estate taxes. 317 C. 185.

Provision directing that all taxes be paid “without apportionment or contribution” is sufficient to overcome statutory presumption of proration; however, such language will only be applied to property clearly contemplated by decedent to be within the estate. 60 CA 665.

Statute is constitutional. 16 CS 149. As a necessary result of the proration act, a widow, in the absence of clear language in the will to the contrary, should take her share free of taxes. 17 CS 401. Testamentary directive against proration must be clear and unambiguous; directive to pay taxes in same manner as other administration expenses held effective against proration of taxes attributable to beneficiaries of residue. 20 CS 471.