“Any interested person” has the right to contest either before or after probate of a Will. California law defines the term “interested person” to include an heir, devisee, child, spouse, creditor, beneficiary, anyone having a property right or claim against the estate that may be affected, anyone having priority for appointment as representative, or a fiduciary.
Who is an “interested person” may vary and must be determined case by case according to the purposes of and issues in any proceeding. The interest must be a pecuniary (or economic) interest in the devolution (or transfer) of the estate that may be impaired or defeated by probate of the Will or benefited by having it set aside.. The beneficiary of an earlier plan can lose standing by violating the no-contest clause in that earlier instrument. For purposes of a Will contest, an executor who is left nothing is not an interested person.