How to Write a Cohabitation Agreement

Genuine Agreement on Specific Terms

Every material term should be spelled out in plain language. If the agreement says rent is "split fairly," that is not a term a court can enforce, but an invitation to argue. If it says each party pays a specific dollar amount by a specific date each month, that is enforceable. Apply the same standard to every provision: if you cannot describe exactly what compliance looks like, the term needs to be more specific.

Written Form and All Signatures

The agreement must be in writing and signed by every person it covers. Oral roommate agreements are very difficult to enforce and disputes almost always come down to one person's word against another's. Courts are reluctant to resolve them. Every housemate should sign, and each person should keep a copy.

Voluntary Execution

No one should sign under pressure or without adequate time to read the document. If someone moves in on short notice and signs the agreement without reviewing it, that circumstance could be raised later as a basis to challenge specific terms. Build in time for everyone to read, ask questions, and negotiate before signing.

Step 1 — Identify the parties and the property

Name every person covered by the agreement and include the full address of the shared residence. Specify each person's role: who is the primary leaseholder (if applicable), who are subtenants, and what each person's right to occupy the property is based on. This section anchors the rest of the agreement to a specific household and a specific group of people.

Step 2 — Establish how rent and household expenses will be divided

Specify each roommate's exact share of rent, how it will be paid, and when it is due. Address all recurring household costs: utilities, internet, streaming services, renter's insurance, and any other shared expenses. Decide whether costs will be split equally or apportioned differently — for example, based on room size, income, or prior agreement — and state those terms explicitly. If a joint account or shared payment app will be used to manage household costs, describe how it works and who has access.

Be specific about what happens if someone does not pay their share on time. A provision addressing late payment — even something as simple as a requirement to notify housemates within 24 hours if a payment will be missed — prevents a small issue from becoming a larger dispute.

Step 3 — Define use of shared spaces

Describe how common areas — kitchen, living room, bathrooms, laundry, outdoor space — will be used and maintained. Address cleaning responsibilities: who is responsible for what, on what schedule, and what standard of cleanliness is expected. If certain spaces are designated for particular uses (a parking spot, a storage area, a home office), note those designations in the agreement. The goal is not to legislate every detail of daily life, but to establish enough structure that everyone knows what is expected.

Step 4 — Set house rules

This section covers the behavioral expectations that most roommate disputes actually center on. Address the following:

• Overnight guests: How many nights per week or month is a guest permitted to stay before being considered an additional occupant? What is the process for notifying housemates about extended guests?
• Parties and gatherings: Are social gatherings permitted? If so, is advance notice to housemates required? Are there limits on frequency or size?
• Quiet hours: What hours are designated for quiet in the home, if any?
• Pets: Are pets permitted? If so, which types, and who is responsible for any damage or additional costs they create?
• Smoking and substances: What are the rules around smoking or other substance use in the home or on shared outdoor spaces?
• Common area items: Who owns shared household items like furniture, appliances, or cookware, and what happens to them if someone moves out?

Step 5 — Address what happens when the arrangement ends

Specify the notice period each roommate must give before moving out — 30 days is common, though the right time frame depends on the lease and everyone's circumstances. Address what happens to the security deposit: who holds it, how it is divided if not returned by the landlord, and what deductions are permissible. If a roommate leaves and a replacement is needed, note whether remaining housemates have the right to approve the new tenant and what process applies.

This section should also address what happens if the arrangement breaks down unexpectedly — for example, if a roommate stops paying rent or violates house rules repeatedly. A written provision describing a notice-and-cure process (written notice of the violation, a defined period to correct it, and a right to terminate the arrangement if not corrected) gives everyone a fair procedure and reduces the risk of abrupt, contested departures.

Step 6 — Execute the agreement properly

Every roommate must sign and date the agreement. Make and distribute a copy to each person at signing — do not rely on a shared digital copy that someone may later claim they cannot access. Store the signed original somewhere secure. Review and update the agreement any time circumstances change materially: a new roommate moves in, the rent amount changes, or the house rules need revision.

Is a cohabitation agreement legally binding?

Yes, a cohabitation agreement is legally binding if it meets the requirements of a valid contract: it must be in writing, signed by all parties, and reflect a genuine agreement on specific, enforceable terms. Courts will not enforce vague provisions — specificity is what gives the agreement its teeth. A properly drafted and executed cohabitation agreement can be enforced in small claims court or through other legal channels.

What should a cohabitation agreement include?

A cohabitation agreement should cover the names of all residents and the property address, each person's share of rent and household expenses, how shared spaces will be used and maintained, house rules around guests, noise, pets, and gatherings, the notice period required before moving out, and what happens to the security deposit. The more specific each term is, the more useful the agreement will be if a dispute arises.

Does a cohabitation agreement need to be notarized?

Notarization is not typically required for a cohabitation agreement. Unlike agreements that touch real property ownership, a standard roommate agreement covering rent splits and house rules does not generally require notarization to be enforceable. That said, notarization adds a layer of evidence that all parties signed voluntarily, which can be useful if the agreement is later disputed. It is a low-cost step worth considering.

Do roommates need a written agreement if they trust each other?

A written agreement is valuable precisely because it prevents disputes that erode trust. Most roommate conflicts are not caused by bad intentions — they arise from different assumptions about what was agreed to. A written agreement surfaces those differences before anyone moves in, when they are easy to resolve. Skipping it because everyone gets along is the most common reason people wish they had one later.