A primary purpose of estate planning is to ensure that your wealth is distributed according to your wishes after you die. But if a family member challenges the plan, that purpose may be defeated. If the challenge is successful, a judge will decide who’ll inherit your property.

Will contests and similar challenges often occur when one’s estate plan operates in an unexpected way. For example, if you favor one child over the others or leave a substantial inheritance to a nonfamily member, those who expected to inherit that wealth may challenge your plan, often on grounds of undue influence. There are steps you can take, however, to avoid these challenges.

Not all influence is undue

It’s important to recognize that a certain level of influence is permissible, so long as it doesn’t rise to the level of “undue” influence. For example, there’s nothing inherently wrong with a daughter who encourages her father to leave her the family vacation home. But if the father is in a vulnerable position — perhaps he’s ill or frail and the daughter is his caregiver — a court might find that he’s susceptible to undue influence and that the daughter improperly influenced him to change his will.

Protecting your plan

Here are several steps you can take to avoid undue influence claims and ensure that your wishes are carried out:

Use a revocable trust. Rather than relying on a will alone, create a revocable, or “living,” trust. These trusts don’t go through probate, so they’re more difficult and costly to challenge.

Establish competency. Claims of undue influence often go hand in hand with challenges on grounds of lack of testamentary capacity. Establishing that you were “of sound mind and body” at the time you sign your will can go a long way toward combating an undue influence claim. Be sure to create your estate plan while you’re in good mental and physical health. Have a physician examine you, at or near the time you execute your will and other estate planning documents, to determine if you’re mentally competent.

Avoid the appearance of undue influence. If you reward someone who’s in a position to influence you, take steps to avoid the appearance of undue influence. Suppose, for example, that you plan to leave a substantial sum to a close friend who acts as your primary caregiver. To avoid a challenge, prepare your will independently — that is, under conditions that are free from interference by family members or other beneficiaries. People who’ll benefit under your estate plan shouldn’t be present when you meet with your attorney. Nor should they be present when you sign your will and other estate planning documents, or serve as witnesses.

Talk to your family. If you plan to disinherit certain family members, give them reduced shares or give substantial sums to nonfamily members. And make sure that you meet with your family as soon as possible to explain your reasoning. If that’s not possible, state the reasons in your will or include a separate letter expressing your wishes. Family members are less likely to challenge your plan if they understand the rationale behind it.

To deter challenges to your plan, consider including a no-contest clause, which provides that, if a beneficiary challenges your will or trust unsuccessfully, he or she will receive nothing. Keep in mind, however, that you should leave something to people who are likely to challenge your plan; otherwise, they have nothing to lose by contesting it.

No guarantees

If your estate plan leaves any family members less of an inheritance than they expect, there’s a risk they’ll contest it. Although there’s no guaranteed way to protect your plan, the strategies discussed above can minimize the chances that a disgruntled beneficiary will challenge your plan in court.