Washington State Cohabitation Agreements
What is a Cohabitation Agreement?
A cohabitation agreement is a contract entered into between unmarried persons who are living together. These agreements are commonly used to memorialize how unmarried persons will divide assets and address other claims during a relationship or in the event of a separation. Cohabitation agreements are not governed by Washington State law, which means these agreements can define "property rights" and "obligations" differently from Washington’s laws governing community property and the just and equitable division of property at the time of divorce. However, in order for a Court to honor a cohabitation agreement, it must be reasonable in its terms, and the parties’ assets must be sufficiently defined , so that the agreement does not fail due to vagueness or ambiguity.
The biggest advantage of a cohabitation agreement is that if one party incurs a debt or liability, or one party receives an asset during the relationship, these occurrences are not viewed as giving rise to an obligation or interest in the other party’s assets or obligations. So, if one party buys something, the item does not necessarily become co-owned by both parties. If one party incurs a debt, the other party may not be responsible for the debt.
Like premarital agreements, cohabitation agreements must be entered into voluntarily and without fraud or misrepresentation. An agreement that is produced under duress or lack of capacity generally is subject to strict scrutiny in court.

Legal Considerations in Washington State
In Washington State, the legal framework surrounding cohabitation agreements falls under the general body of contract law. Cohabitation agreements are governed by the principles of contract formation and interpretation. They are generally treated similarly to prenuptial agreements and not particularly different from any other contracts. Despite the increasing popularity of cohabitation agreements, Washington does not have a state-specific statute regarding their enforcement or formulation. Like other contracts, cohabitation agreements must adhere to the requirements of basic contract formation, which requires that the terms of the contract be sufficiently clear and definite. The portions of the Washington Administrative Code that deal specifically with cohabitation agreements are limited to issues concerning the creation, interpretation or enforcement of provisions pertaining to children. A proposition initially conceived in Texas, cohabitation acts allow for the creation of enforceable cohabitation agreements by establishing that a couple who cohabitates possess any additional rights or remedies concerning economic issues of partnership or marriage. Washington is one of 11 states that has no such cohabitation act.
Washington treats any agency relationship created between two unmarried individuals as a contractual relationship. The Washington Court of Appeals has stated that such contracts can be express or implied, but contracts between unmarried persons do not require the same formalities that a contract between married persons might require. In Washington v. Taliaferro, the Washington Court of Appeals reiterated this notion while also noting that "contracts among unmarried persons are govern by the same rules of contract construction that apply to contracts among married persons." As such, Washington may not impose restrictions on the formation of cohabitation agreements that would not apply to other contracts. These contracts are enforceable similarly to any other contract, as long as a legally enforceable agreement has been reached by the parties. There is substantial public policy favoring the enforcement of cohabitation agreements, which has been upheld by courts.
Reasons for a Cohabitation Agreement
Cohabitation agreements can help you avoid expensive litigation should your relationship end. Cohabitation agreements are far less complicated than prenuptial agreements, and are relatively inexpensive to have prepared by an experienced attorney. Because of their simplicity, these agreements can be prepared much cheaper than a divorce would cost should the parties not have a cohabitation agreement.
Usually, a cohabitation agreement will identify each party’s individual asset and debts. It will define what property will be considered joint property subject to division if the relationship ends. The agreement can redefine how debt incurred during the relationship will be allocated after a separation.
Another benefit of a cohabitation agreement is the ability to allocate the payment of household bills and expenses. In the event of a separation, it can be very litigated whether expenses paid on a mutual house mortgage, for utilities, insurance, and maintenance should be reimbursed to the party who paid them. A cohabitation agreement can clearly define this in advance of any separation.
Importantly, a cohabitation agreement should address what obligations each party has towards the payment of alimony to the other in the event of a separation. Washington courts routinely award alimony to former spouses. Washington courts have held cohabitating unmarried parties may also have alimony obligations to their former partner.
In short, it is likely a cohabitation agreement can save you thousands of dollars if your relationship ends. If you are in a committed relationship, but are not legally married, then you should consider having an attorney prepare a cohabitation agreement for you.
Necessary Components of a Cohabitation Agreement
One of the most common reasons a cohabitation agreement gets drafted is to specify how property will be divided between the parties in the event of the end of the relationship, or perhaps upon death of one of the parties. Therefore, it is important to consider what assets will be pre-marital assets vs. marital assets, as well as debt payments. It is also crucial to consider and specify how assets and debts will be divided in the event of a breakup or death.
Determine if each party will retain their separate property, even if the title is held in both names. It is also important to designate whether assets acquired during the relationship will be considered marital, and subject to division. Include how debts acquired during the relationship will be paid, and how a significant amount of debt will be paid off or addressed.
Although this issue is more relevant for a post-nuptial agreement , you may want to include in the cohabitation agreement how bills will be paid. Will they be split equally, or in a proportionate fraction to income? It is also important to anticipate the cost of raising children. While courts proffer child support guidelines, these guidelines cannot be addressed in a cohabitation agreement; such guidelines can only be addressed in a child support order, which is required by law when there are children.
For example, if a party has children from a previous relationship and those children will be living in the home with the party, will that party be able to pay rent if he/she is responsible for child support for the children? Will the other party be expected to contribute for the children? Again, while child support cannot be established in a cohabitation agreement, parties can agree to contribute proportionally.
Challenges in Enforcing a Cohabitation Agreement
The enforceability of a cohabitation agreement in Washington State, like most contracts, hinges on a variety of factors. The terms stated in the contract must be clear and not misleading. If they are unclear or confusing, the courts may have a difficult time enforcing those terms. Both parties must also have had the ability to be represented by legal counsel when drafting the post-nuptial agreement. As with all contracts, the best way to draft a cohabitation agreement is to do so with qualified legal counsel. Leaving it up to the parties without any legal representation creates a situation ripe for challenge. Cohabitation agreements are relatively new in Washington State, and as such the courts are reluctant to enforce them. In Washington, there have been few challenges. However, in a 2004 decision a succinct set of requirements was clearly stated.
When considering a motion to enjoin the enforcement of a [Cohabitation] Agreement, the following factors are most relevant: (1) Whether the party challenging the agreement will suffer irreparable harm; (2) Whether the party seeking to enforce the agreement will suffer substantial harm if the agreement is not enforced in the interim; (3) Whether the party seeking to enforce the agreement will be irreparably harmed if the court fails to give the agreement immediate effect. A party seeking to enforce a contract and another party seeking to prevent enforcement of that contract will always have two vouchers available to them: irreparable harm and harm to their counterpart. However, the courts must look closely at these factors to ensure their proper meaning is being applied. It is particularly important that a cohabitation agreement be drafted by an attorney thoroughly acquainted with the law and with what is needed to create an enforceable agreement. Without this, a cohabitation agreement can become a great deal of effort for little reward.
Conclusion: Planning Ahead
When it comes to preparing for the possibility of a relationship ending, there is no substitute for a well-written cohabitation agreement in Washington State. Thorough, clear language that outlines each party’s rights and responsibilities is essential to avoid conflict and confusion when it comes to dividing assets and debts. A separation or divorce is undoubtedly one of the most trying times in a person’s life, and you do not want to have to make important decisions regarding your future during such a stressful time .
Having a neutral third party take care of important issues regarding your assets and property beforehand does not just take some of the burden off you during a separation, but it also ensures that your wishes will be heard. Without the pre-established guidelines of a legally binding contract, you may find yourself overwhelmed with problems.
For these reasons, it is can be crucial to consult with a legal professional when drafting or reviewing a cohabitation agreement in Washington state. Unless you are completely familiar with the laws surrounding legal contracts, you could easily miss important details or unintentionally include language that could later be deemed too vague or contradictory.