When a loved one passes away, the probate process is meant to honor their final wishes. Family members or beneficiaries who believe a will does not reflect the decedent’s true intent, or was created under suspicious circumstances, have the right to contest it. Interested parties may challenge a will’s validity during probate proceedings by establishing specific grounds under Arizona law.
Lack of testamentary capacity
To execute a legally binding will in Arizona, a person must be at least 18 years old and of sound mind. A capacity challenge asserts that at the precise moment the will was signed, the testator lacked the mental ability necessary to understand the transaction. Arizona case law requires showing that the testator failed to understand:
- The nature and extent of their property and estate assets
- The natural objects of their bounty, meaning their immediate family members or likely heirs
- The overall legal effect of the document being executed
A diagnosis of dementia, Alzheimer’s disease, or cognitive decline does not automatically invalidate a will. The legal inquiry focuses on whether the individual experienced a lucid interval at the time of execution. Medical records, physician testimony, and statements from the drafting attorney are all relevant evidence in these disputes.
Undue influence under Arizona law
Undue influence occurs when a third party exerts pressure that overrides the testator’s free will and substitutes the influencer’s desires for those of the decedent. The contestant bears the initial burden of proving undue influence. Arizona courts have recognized that a presumption of undue influence may arise when a contestant demonstrates four factors drawn from case law:
- A confidential relationship, such as serving as a power of attorney, caregiver, or financial advisor
- Active participation in procuring, drafting, or arranging the execution of the will
- A substantial or disproportionate benefit received under the disputed will
- A weakened physical or mental condition that rendered the testator vulnerable to manipulation
Once sufficient evidence of these factors is presented, the burden shifts to the will’s proponent to show it was executed freely and voluntarily.
Procedural deadlines for contesting a will
Timing matters in Arizona will contests. For informally probated estates, interested parties generally have four months from receiving formal notice of probate to file a petition. For formal proceedings, objections must be filed before the court hearing designated to approve the will. Missing these deadlines can bar an otherwise valid challenge.
Getting guidance early
Will contests involve complex evidentiary standards and formal probate litigation under tight deadlines. If you believe a will was executed without proper capacity or under undue influence, a probate litigation attorney in Arizona can help you evaluate your grounds and act within the required timeframes.

