Short Answer
If everything was set up correctly in the first place, it is probably unnecessary to open up either an informal probate case or a formal probate case, although it may be necessary to prepare a small estate affidavit. But, there aren't enough facts in your question to know for sure.
There are also a couple of documents that have to be filed or recorded with regard to the trust, but those documents aren't part of either a formal probate or an informal probate.
If there is a will, however, (and it appears that there is) it needs to be lodged with the court even if there is no formal probate and there is no informal probate.
You Are Almost Surely Confused About The Facts
Family trust was set up with:
a quitclaim deed transferring the home into the trust, and
a parent's pourover will that left the home first to a single
beneficiary, and second, if that beneficiary died then to other
beneficiaries.
If it was set up this way, somebody made a serious mistake. (Your mention of a holographic will worries me because it suggests that somebody didn't use a lawyer to set this up in which case they probably screwed it up.) But, I suspect that you misunderstand the situation.
Normally, you would set up a revocable trust (also known as a "living trust") and quitclaim the home into the trust, and use a bill of sale to transfer all tangible personal property into the trust, and title all bank accounts and investment accounts in the name of the trust. Then, the provisions of the trust (not the will) would say which beneficiary received the trust's assets.
Assets in a trust are governed by the terms of the trust and the terms of any will are disregarded with respect to the assets in the trust.
A pourover will, by definition, is a will that leaves any property that is not in the trust on the date of death to the trust (which ceases to be a revocable trust and becomes an irrevocable trust upon the date of death).
A pourover will is only used if there are assets on the date of death that are not titled in the trust and that do not pass by another non-probate transfer (i.e. a beneficiary designation or a joint tenancy with right of survivorship or a lifetime transfer to a beneficiary before death or property in a trust created during life).
A will has no authority to direct the disposition of property that passes via a non-probate transfer. Instead, a will only applies to probate property.
Probate property is property owned by the dead person which does not have a beneficiary designation or survivorship provision and is not in a trust.
Lodging The Will
If there is a will, it must be delivered to the court of general jurisdiction in the county where the person who died resided by the person who is in possession of it, within a certain number of days after the death of the person who wrote the will, even if there is no need for a formal probate or an informal probate, and even if the person who is in possession of the will doesn't know if it is valid or not.
When Is Probate Required?
Possibility One: There Is No Probate Property
Ideally, all property would be in the trust as of the date of death. In that case, there would be no probate (informal or formal), because property in a trust is one kind of property that passes via a non-probate transfer.
All property that does not pass by a non-probate transfer is probate property.
Possibility Two: There is no probate property which is real estate and all of the probate property combined is worth $42,000 or less.
If there is probate property, then you have to determine if a probate proceeding, either formal or informal, is required, or if instead probate can be dispensed with entirely.
If the total amount of probate property is less than the amount of the exempt property and family allowance amounts under the probate code (Title 75 of the Utah Statutes) (which is $42,000 as of 2010, although it appears from the Utah State Legislature website that this has not changed since 2010), and there is no real estate that is outside the trust, then the probate property may be transferred by a small estate affidavit of the person named as personal representative (PR a.k.a. executor) in the Will without opening up an informal probate or formal probate, if all of the people whose consent is necessary to make the transfer (such as the DMV for a car, or a bank handling a final paycheck or tax refund) will accept the affidavit in lieu of letters testamentary.
If a small estate affidavit is sufficient to transfer all of the probate property in this situation, then there is no probate proceeding, formal or informal.
Possibility Three: There is probate real estate, or there is probate property worth more than $42,000, or someone in control of probate property refuses to accept a small estate affidavit.
If there is real estate outside the trust, or if the total value of the property outside the trust that does not pass by non-probate transfer is worth more than the combined exempt property amount and family allowance (i.e. if it was more than $42,000), then you must probate the will, either formally or informally, and have the PR appointed by the court registrar. Then, as PR, the PR can transfer all of the probate property to the trust and close the estate.
The only time that a will can have any validity, in the absence of an informal probate or a formal probate, is when the estate qualifies for a transfer by affidavit. And, in practice, lots of third parties other than the DMV will balk at accepting an affidavit, so it is usually easier to simply do an informal probate, than it is to bother with an affidavit.
Formal v. Informal Probate When Probate Is Required
Informal Probate
An informal probate is very easy, although you should still have a lawyer at a minimum assist you in filing it and in closing the estate when you are done.
There are standard court forms to commence an informal probate that are mostly pretty straightforward to fill out, and once the forms and original will are delivered to the court of general jurisdiction where the person who died resided the clerk in charge of probate cases called the Registrar reviews it and if everything is in order, immediately stamps them and gives the PR his or her "letters testamentary" (that give the PR the authority to transfer the property to the trust) without holding any hearings or even talking to a judge.
An informal probate is only allowed if there are no disputes in the case regarding the validity of the will or the appointment of the person named in the will to be the PR. An absence of dispute is shown in an informal probate by having everyone with a right to dispute the will or the PR appointment sign a consent form which is included in the package of forms submitted to the court in an informal probate.
The letters testamentary issued to the PR in an informal probate expire when the probate case is closed, which is done by filing a one page court form with the court that certifies that all of the probate assets of the person who died, and all of the debts of the person who died, have been taken care of by the PR.
A case that starts out as an informal probate can be converted to a formal probate if after letters testamentary are issued by the registrar in the informal probate (which often happens the same day that the case if filed), someone contests the will before the case is closed.
When that happens, everyone starts over from scratch to determine if the will is valid and if the right person was appointed as PR, but in the meantime the person appointed informally continues to act as PR in a caretaker capacity (without making any distributions to heirs or devisees) until the validity of the will and the validity of the informal appointment of the PR is resolved.
Formal Probate
A formal probate is only necessary if (1) there is a dispute regarding the validity of the Will, or (2) regarding the person entitled to be PR, or (3) if the Registrar (i.e. the clerk of the court in charge of probate matters) in the Registrar's sole discretion feels that it doesn't smell right and refers it to a judge.
Realistically, formal probates are only brought when (1) there is a bona fide dispute over the validity of the will or (2) when someone with a right to contest the will can not be located to sign off on a consent or can't be bothered to sign and return it. When probate cases are filed they are filed formally maybe 5%-10% of the time and bona fide disputes are only present maybe 1%-2% of the time (less than 20% of formal probates).
If there is not a bona fide dispute, a formal probate is really just a pro forma bump in the road and is no big deal. Your lawyer schedules a hearing, gives formal notice to everyone entitled to notice (basically all family and anyone named in a current or prior will who is still living), lines up a witness or two, and if anyone file a will contest, actually conducts the hearing.
If no one files a will contest, then the judge, issues letters testamentary to the PR, and the remaining probate case is no different than an informal probate.
If someone does file a will contest, then the judge conducts a will contest hearing (with a jury if one was demanded in the will contest) and if decides which will, if any, is valid and who is entitled to be the PR. A pretty hotly contested will contest trial before a judge without a jury lasts about two or three days (usually after a few months to allow the parties to prepare for the trial). Once letters testamentary are issued and a PR is appointed following that hearing, a formal probate is the same as an informal probate.
Supervised Administration.
In very rare cases, maybe one in 200 to one in 500 cases, there are heated disputes about almost every issue related to administering the probate estate and a party requests and is granted permission to conduct a supervised administration.
It is possible to have a supervised administration even in an informal probate, if there is no dispute over which will is valid, or who the PR should be, but there is great dispute over how the PR should handle the administration of the probate estate that posting a bond isn't sufficient to address.
In a supervised administration, the PR must obtain pre-approval from the judge to do anything (which is how probate usually works in states that didn't adopt the Uniform Probate Code the way that Colorado and Utah did). This is much, much more expensive.
What Formalities Are Necessary For The Trust
Whether or not there is a probate proceeding or a small estate affidavit, if there is a trust, the trust must comply with certain formalities.
If no probate is required, but there is a trust, the trustees by a deadline set in the Utah Probate Code have to file a "trust registration statement" which states the date that the trust became irrevocable (usually either the date it is formed or the date the person creating it died), the name and contact information of the trust, and the county where the trust records are kept which is also the county were the trust "resides" for lawsuit purposes.
The trust must also obtain a taxpayer identification number from the IRS and file Tax Form 1041 and the parallel state tax form every year that it has more than $600 of income.
In connection with a transfer of real property out of the trust, the trust will need to prepare and record in the real property records of the county where the real estate is located, in addition to the deed, a document which is basically an affidavit, proving that the person who is signing the deed as the trustee is really the trustee and authorized to sign the deed.
