The purpose of this Regional Supplement is to explain the estoppel principle and when and how it should be considered applied.

To enhance FOs understanding, included are examples that illustrate various situations in which estoppel should be considered and/or applied.

A divorce is valid if it was issued in a State or foreign country where at least one of the parties was domiciled. Such divorce will be recognized in other States if the court of the State that issued it had jurisdiction (GN 00305.170). However, even if the W/E's divorce is invalid under the law of his/her domicile, the principle of estoppel may prevent the other party to the divorce from denying its validity.

In such case, the estopped party is precluded from becoming entitled to benefits as his/her spouse.

The Office of Chief Counsel (OCC) defines estoppel as, "a term applied to a situation where, because of something which he/she has done or omitted to do, a party is denied the right to plead or prove an otherwise important fact. The purpose of estoppel is to promote equity and justice in an individual by preventing a party from asserting rights under a general rule of law when his own conduct renders that assertion contrary to equity and good conscience."