Do This Before Buying A House As An Unmarried Couple

August 3, 2026

By Nadia Cabrera-Mazzeo, Esq.

Short Answer: A cohabitation agreement can set clear expectations and legal protections for co-ownership

More and more couples are building lives together and making long-term commitments to each other without marriage. This might include buying a house together. When you own property with someone, you are legally tied to that person even if the relationship breaks down. There are some important decisions that need to be made about co-ownership before you actually buy the house and certainly before things get so messy that you’re no longer in a place of collaboration. A cohabitation agreements forces you to answer these questions and resolve potential issues before they arise.

What is a cohabitation agreement?

A cohabitation agreement is a legally binding contract between you and your partner establishing the legal rights and expectations for co-ownership. Your cohabitation agreement might cover things like:

.    Changing the default ownership rules so that if one of you passes away, the other person gets full ownership of the house;

.    Establishing what is considered shared property and how you will manage shared finances;

.    Protecting each other from the other person’s debts or other obligations;

.    Deciding upfront what to do with the house and other shared property if the relationship ends.

Breakups are hard and messy even in the best of circumstances. It’s best to make these important decisions with clear heads and hearts.

What happens if you don’t have a cohabitation agreement?

Buying property together without setting clear rules and intentions for co-ownership could have unexpected consequences. For example, if you don’t decide beforehand what you want to happen if one of you passes away, it’s possible that the law will decide for you. In that case, it will likely decide that if one of you passes away, that person’s next-of-kin will own 50% of the house. That can get messy very quickly, and the deceased partner’s successors could force a sale of the house even when the other partner still lives there.

Another potential consequence is being caught unprepared if the relationship ends and having to act quickly if you want to keep the house. When a co-owner wants to remove themselves from the situation, they are legally allowed to force a sale without the other person’s permission. To avoid this type of one-sided control over the sale, the cohabitation agreement will set expectations for a buyout or joint sale if the relationship ends.

Cohabitation agreements create rights and obligations to each other that can be legally enforced

Cohabitation agreements usually require that the partners be honest and deal with each other in good faith. Because co-ownership involves an important financial relationship, the obligation to be truthful about each partner’s finances can have real-world consequences if one partner breaks those promises and causes the other partner to suffer financial harm. In that case, the injured partner could hold the other legally accountable under contract law. This remedy is not available to unmarried couples who buy property together without an agreement.

Law office of Nadia Cabrera-Mazzeo, Esq.

Small business and contracts lawyer

Based in Albuquerque, serving clients throughout New Mexico

505 427 2025

nadia@honestcontracts.com

PO Box 6825, Albuquerque, NM 87197

The information on this website is not legal advice and does not create an attorney-client relationship. The rates and fees listed on this website may not be the most up to date.