Quick answer: the most common mistake is never recording a new deed into the trust's name for real estate. Idaho adds a second, quieter risk: mischaracterizing community property during funding. Either mistake is still the family's own responsibility to avoid. See how the numbers change in the Idaho probate vs living trust calculator.
Signing ≠ funding
1. Real estate deed never recorded — the #1 mistake
Moving real estate into a trust requires a new deed, signed and recorded with the county recorder, naming the trust as owner. This is the step most often skipped. Left undone, that property remains a probate asset — subject to the full District Court process, regardless of the trust document sitting in a drawer.
2. Mischaracterizing community property — Idaho's own risk
When a married couple funds a joint trust with community property, both spouses should sign as settlors so the property's character doesn't change. A trust drafted from a generic, common-law-state template, or funded with only one spouse's signature, can inadvertently convert community property into separate or ambiguous ownership — risking the double step-up in basis discussed in the Idaho probate vs living trust comparison. This mistake can cost far more in lost tax basis than anything saved on attorney fees.
3. Financial accounts left titled individually
Bank and brokerage accounts don't join a trust automatically. Each one has to be retitled into the trust's name, or the institution needs a copy of the trust document plus a change-of-ownership form. Accounts opened after the trust was created are especially easy to forget.
4. Treating the small estate affidavit as a safety net
Idaho's small estate affidavit — $100,000 or less net, personal property only — is a genuine shortcut for modest, unfunded assets. It is not a backstop for a house or a sizeable account left outside the trust by mistake; those amounts require full probate, regardless of the unused trust document.
A local probate attorney can review your estate — many offer a free consultation.