If the deceased set up a revocable living trust and actually moved their assets into it, no one needs a letter of testamentary with a trust to manage or distribute those assets. The successor trustee’s authority comes from the trust document itself, not from a court. Letters of testamentary only enter the picture for assets that were left outside the trust and have to pass through probate under a will. Whether you need one comes down to how each individual asset was titled at the moment of death.
Why a Trust Doesn’t Require Court Authorization
A revocable living trust owns the assets that have been transferred into it. When the grantor dies, legal ownership of those assets doesn’t have to move through a court proceeding, because it never sat in the grantor’s personal name to begin with. The successor trustee named in the trust document steps in immediately and manages everything according to the trust’s terms. No petition, no judge, no waiting period.
That’s the core difference between an executor and a trustee. An executor gets authority from the probate court and can only act after the court grants it. A trustee gets authority from the trust instrument and can contact financial institutions, sell property, and distribute assets to beneficiaries as soon as they’re ready to act.
Once the grantor dies, the revocable trust becomes irrevocable. Its terms can no longer be changed. The successor trustee owes fiduciary duties to the beneficiaries: a duty of loyalty, meaning beneficiaries’ interests come first, and a duty of prudent management of trust assets. Breach exposes the trustee to personal liability. These duties apply whether or not a court is supervising.
How a Trustee Proves Authority Instead
Where an executor hands a bank a letter of testamentary, a trustee hands over a certification of trust. This document confirms the trust exists, identifies the current trustee, describes the trustee’s powers, and specifies how trust property should be titled. It does not disclose the trust’s distribution terms or name the beneficiaries, which is what preserves the privacy advantage trusts have over wills.
Most states have adopted statutes that let trustees present a certification of trust rather than the full trust document. A third party who relies in good faith on a valid certification is protected from liability even if the certification later turns out to contain errors. Institutions that unreasonably insist on seeing the entire trust instrument can face liability for the delay they cause.
When You Need Letters of Testamentary Even Though There’s a Trust
The common scenario is straightforward: the grantor didn’t get every asset into the trust before dying. A house still deeded in the grantor’s personal name. A bank account that never got retitled. An inheritance received a few months before death. Any asset sitting outside the trust at the moment of death has to be handled through probate, and the person handling probate needs letters of testamentary to do it.
This is what a pour-over will is for. A pour-over will acts as a safety net, directing that any assets left outside the trust at death be transferred, or “poured,” into it. The catch is that a pour-over will is still a will, and it has to go through probate like any other. The executor uses letters of testamentary to collect those stray assets and move them into the trust, and the trustee then distributes them under the trust’s terms.
Neither role outranks the other. Authority follows title. If an asset is in the trust’s name, the trustee handles it. If it isn’t, the executor has to open probate to reach it. When the will’s instructions and the trust’s terms appear to conflict, a court usually has to sort it out.
Assets That Bypass Both the Trust and Probate
Some assets pass to a named beneficiary regardless of what any will or trust says. Life insurance policies, retirement accounts like 401(k)s and IRAs, and bank accounts with payable-on-death or transfer-on-death designations all move directly to the person named on the account form. Property held in joint tenancy with right of survivorship transfers automatically to the surviving owner.
Beneficiary designations override both wills and trusts. If a trust directs a retirement account to one person but the account’s beneficiary form names someone else, the beneficiary form controls. This is where estate plans quietly fall apart. Someone updates a trust after a divorce and forgets to change the beneficiary designation on an old life insurance policy, and the ex-spouse collects. Reviewing beneficiary designations alongside the trust is one of the most overlooked parts of estate planning.
Why Trusts End Up Needing Probate Anyway
An unfunded or partially funded trust is one of the most common estate planning failures. The grantor signs the trust documents and treats the job as finished, but never actually retitles assets into the trust’s name. The trust exists on paper and controls nothing. When the grantor dies, those assets go through probate exactly as if the trust had never been drafted.
Funding a trust means changing legal ownership. Real estate needs a new deed naming the trust as owner. Bank and brokerage accounts have to be retitled to the trust. Each institution has its own paperwork. The process is tedious, which is why people skip it and why estate planning attorneys see the consequences over and over.
The fallout is more than inconvenience. Probate adds months of delay, court costs, and attorney fees that the trust was designed to avoid. It also makes the estate a matter of public record, eliminating the privacy the trust was supposed to provide. Beneficiaries face a gap between the death and the point when they can actually access anything, and creditors get a window to file claims they might not have had against a properly funded trust.
Trust funding is worth reviewing periodically, and especially after buying property, opening new accounts, or going through marriage or divorce. That review is what separates an estate plan that works from one that produces the exact problems it was supposed to prevent.
What the Successor Trustee Still Has to Do
Skipping probate is not the same as skipping paperwork. Once the grantor dies, several obligations land on the successor trustee.
Get an EIN for the Trust
While the grantor was alive, the revocable trust typically used the grantor’s Social Security number. Once the grantor dies and the trust becomes irrevocable, the trust needs its own Employer Identification Number. The successor trustee applies using IRS Form SS-4, which can be completed online at irs.gov. Income earned by trust assets after the grantor’s death gets reported under the new EIN, not the decedent’s Social Security number.
File Trust Income Tax Returns
An irrevocable trust with any taxable income has to file IRS Form 1041, the income tax return for estates and trusts. For calendar-year trusts, the deadline is April 15 of the following year. If the trust distributes income to beneficiaries during the year, those beneficiaries receive a Schedule K-1 reporting their share and include it on their personal returns.
Check Federal and State Estate Tax
For 2026, the federal estate tax exemption is $15,000,000 per person. Estates below that threshold generally owe no federal estate tax and don’t need to file a federal estate tax return. Estates above it face a top marginal rate of 40% on the excess. The exemption was set by legislation signed in July 2025.1Internal Revenue Service. What’s New – Estate and Gift Tax Married couples can effectively double the exemption through a portability election, but only if the first spouse’s estate files the appropriate return even when no tax is owed.
Some states impose their own estate or inheritance taxes at much lower thresholds. A trust that owes nothing federally may still owe something at the state level, so the trustee should check the rules of the state where the grantor lived and where trust property is located.