How does a prenuptial agreement affect estate planning?

Judges in most cases honor and enforce (signed and notarized) prenuptial agreements between two spouses as long as both parties entered it freely and voluntarily and with full knowledge of one another financial circumstances, and the agreement is not "unconscionable." A prenuptial agreement may not be enforced if (1) either party signed it under duress or coercion or undue pressure (or, say, the night before the wedding), (2) the party seeking to enforce it did not truthfully and completely disclose their financial information, or (3) enforcing the prenup would leave one spouse so destitute that they could not meet their most basic living expenses (i.e., would be forced onto welfare). In short, the prenuptial agreement will be enforced if (1) all the procedural requirements were met at the time it was signed and (2) the terms are not unconscionable, taking into account the circumstances existing at the time of divorce.

A prenuptial agreement does not in itself affect how taxing authorities will treat the spouses. But it can create promises between the spouses toward one another. For example, it may create a promise to file jointly, or specify that they are making no such promise. And it can create a promise by each spouse to pay the other back for any taxes the other pays on his or spouse's behalf. The decision whether to file jointly or separately does have tax implications with taxing authorities.

Texas calls prenuptial agreements "Premarital Agreements". These agreements, just like any other contract, can be challenged in court. A challenge to the agreement does not mean it will be found invalid, however. Surviving a challenge to the premarital agreement is primarily accomplished all the way back to when the agreement is drafted and executed. There are requirements or prohibitions for the agreement terms to be valid, which are too numerous to list here, but can be found in the Texas Family Code, chapter 4. In Texas, no consideration is required, but the Agreement must be in writing, and signed by both parties. It must be free from fraud and duress, and entered into voluntarily. It cannot be unconscionable, and the parties must provide a fair and reasonable disclosure of the property and financial obligations (unless waived). Enforcement of a premarital agreement falls under the Texas Family Code 4.006. Additionally, any provision that would adversely affect the support of children is going to be prohibited. Conservatorship and possession/access (custody and visitation) will always be determined by the Court under the best interest of the children standard, regardless of what may have been put into the agreement. The best way to survive a challenge is to hire a competent attorney to draft the agreement, ensure the agreement complies with the Texas Family Code, provide a fair and reasonable disclosure from both parties, both parties being represented by their own attorney when entering into the agreement, and ensuring the agreement is available for review far in advance of the wedding date.

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A prenup would be binding in a divorce action provided that the prenuptial agreement was written properly, both parties disclosed all relevant financial information along with an acknowledgement that they had the right to consult an attorney of their own choosing before signing, and the signing was witnessed by a notary.