Oral Trusts in Arizona: What the Law Requires as Proof

Oral Trusts Are Legal but Hard to Prove

Most people associate trusts with formal, signed documents. The law takes a broader view. A trust need not be evidenced by a trust instrument to be valid. But proving that an oral trust was created is a much higher bar than proving the terms of a written one.

Clear and convincing evidence is a demanding standard. It means the evidence must be highly and substantially probable, not just more likely than not. Anyone claiming a trust is created through oral agreement would need testimony, documentation, or other proof strong enough to leave little room for doubt about the settlor's intentions.

Written Trusts Require Written Changes

The second half of this statute draws an important line. Once a trust is created by written instrument, it can be amended or revoked only by written instrument executed by the settlor. You cannot modify a written trust with a verbal instruction, a phone call, or a casual conversation.

This rule protects settlors and beneficiaries alike. It prevents disputes over whether someone verbally changed the terms before passing away or becoming incapacitated. Anyone who claims a written trust was "really" supposed to say something different would need to go through the formal amendment process.

For practical purposes, this is one of the strongest reasons to put a trust in writing from the start. A trust that is created by written instrument and evidenced by a trust document is clear, verifiable, and far more difficult to dispute than an oral arrangement that may come down to one person's word against another's.