Unusual behavior of assistant, caretaker, relative, or if a testator is acting unusual, may give dissatisfied heirs a reason to contest the will on the basis of diminished capacity.
Unequal Treatment
Unequal treatment of children or other stated beneficiary. Siblings treated inequitably in inheritances are more likely to contest a will.
Disinheritance
Disinheritance of close family members in favor of a distant relative, friend or charity. Will contests based on assets passing out of the traditional family are more likely today than ever because of societal changes that include more divorces, cohabitation and same-sex relationships, as well as charities and childless marriages.
Sudden Changes
Sudden or significant change in disposition of assets. When someone suddenly changes a bequest, the beneficiaries of a previous will may be more likely to challenge the new will in court.
Restrictions
Restrictions may seem excessive to beneficiaries on inheritance and they may have expected a windfall benefit.
Beneficiaries may contest the will if they feel that certain restrictions or conditions made on the inheritance by the testator are excessive or unreasonable.
Family Business
Families who own lucrative businesses can get into a tangle if a clear plan is not crafted for succession and for fairly compensating spouses and children who may not be involved in the business.
Mental Health and Capacity
Mental health of testator, senility, Alzheimers, or improper doctor review and management may be cited.
If a testator is elderly or disabled, unhappy heirs may try to claim lack of testamentary capacity or undue influence.
Remarriage
The estates of those who marry for a second or third time and have children from multiple marriages are often litigated if their estate plan doesn't provide adequately for the children of the first marriage and a subsequent spouse. To help guard against this attack, be sure to have a Private Asset Trust plan in place and appoint an independent fiduciary or trustee for the estate plan.
The Family Residence
It is not uncommon for a relative to move into the family home to care for an elderly parent. However, when that parent dies, the relatives often battle over who gets the house. There should be a trust stipulating that the caregiver who moved in may be compensated, but needs to take out a mortgage to fairly compensate other relatives.
Fraud
This is especially prevalent in situations where one child is caring for an elderly parent and begins to believe they are entitled to more than the other children. Changes to bank or investment accounts to pass to one child often leads to litigation.