In some states the beneficiaries of a will may agree among themselves as to the distribution of the property left to them and agree not to probate the will. This is the family settlement doctrine—and is supported by the general principle that the property belongs to the beneficiaries under the will and since they may divide the property as they wish (by transfers made immediately after the distribution), there is no reason why they may not divide it by agreement before they receive it in the regular course of judicial administration of the estate.

For this reason—and because such agreements tend to put an end to family controversies by way of compromise—family settlement agreements are favored in law. And in some states a family settlement in which all the heirs and beneficiaries agree that a purported will shall not be probated is valid and enforceable.

Thus, a will can be contested on the grounds that the person offering the will for probate (proponent of the will) agreed in a family settlement agreement not to probate the will.

In Washington State, the concept of informal probate or family settlement agreements is recognized and can be a practical alternative to formal probate proceedings. Beneficiaries of a will may enter into a family settlement agreement to distribute the decedent's property among themselves without going through the court. This is often done to avoid the costs and time associated with formal probate, and to resolve potential disputes amicably. Such agreements are generally favored by the law as they promote family harmony and can be a more efficient way to settle an estate. However, it is important to ensure that all beneficiaries agree to the terms of the settlement and that the agreement is in compliance with Washington State laws. If a family settlement agreement is in place, and all parties have consented, a will may not need to be probated. Additionally, if a will is contested on the basis that there was an agreement not to probate it, such an agreement can be a valid defense if it can be proven that all interested parties had agreed to the family settlement.