This is not the kind of question I can answer well in this format. I am an Estate and Tax Attorney but I would never advise on the 645 election (and no one else should either in my opinion) without reading the trust and knowing what assets are included as well as the amount of the trust.
Normally, the 645 election is fine under the situation you describe above, but I would highly suggest you seek the advice of a tax professional that can read the documents before you decide. Good luck!
If the trust is a Qualified Revocable Trust, Internal Revenue Code section 645 provides an election for a revocable trust to be treated as part of the decedent’s probate estate for income tax purposes. At the time of the grantor’s death, the beneficiaries may elect to file Internal Revenue Service Form 8855 to -- as the form is aptly named -- “elect to treat a qualified revocable trust as part of an estate.” This accomplishes a few tax benefits. The trust becomes a part of the decedent’s overall estate and is taxed along with it on one tax return. This allows the taxes to be reported on a fiscal year basis, rather than a calendar year, giving more time to prepare for the impending taxes. It also affords the revocable trust any charitable tax deductions as applicable to donations established within the trust that have not yet been paid. Should the decedent have an existing estate outside of his qualified revocable trust, the trust’s beneficiary and the estate representative may elect to combine the two units into one to handle any federal income tax obligations all at once.
