How to Write a Casual Agreement That's as Enforceable as Possible

Let's get the uncomfortable truth out of the way first: most casual agreements between individuals aren't legally enforceable contracts. They lack the formal elements that courts require — like consideration, clear offer and acceptance, and sometimes the involvement of attorneys.

But that doesn't mean your agreement is worthless. A well-written casual agreement does three important things: it clarifies expectations, creates a reference point for resolving disputes, and demonstrates that both parties took the arrangement seriously. And if things ever did end up in a legal setting, a clear written agreement is far better than nothing.

Here's how to write one that carries as much weight as possible.

Understanding Why Most Casual Agreements Aren't Enforceable

Before you can write a stronger agreement, you need to understand what typically makes them weak. For a deeper dive, see why casual agreements aren't contracts and what makes a contract enforceable.

The main issues:

• No consideration. In contract law, both parties need to exchange something of value. Many casual arrangements don't have clear, mutual consideration.
• Vague terms. "We'll hang out sometimes" isn't enforceable. Courts need specifics.
• Illegal or unconscionable terms. Any terms that violate the law or are grossly unfair to one party will be thrown out. See unconscionable terms to avoid.
• No evidence of mutual agreement. If there's no proof that both parties understood and accepted the terms, enforcement is nearly impossible.

10 Principles for Writing Stronger Agreements

1. Use Clear, Specific Language

The biggest difference between a weak agreement and a strong one is specificity. Compare:

Weak: "Financial support will be provided regularly." Strong: "Party A will provide $X via [payment method] on the 1st and 15th of each month, beginning [date]."

Specific terms leave less room for misinterpretation and, if ever challenged, show that both parties had a clear understanding of the arrangement.

For guidance on avoiding legal jargon while staying precise, see plain language vs. legal language.

2. Include Dates

Every agreement should include:

• The date it was created
• The date it takes effect (if different)
• Any relevant deadlines or review dates
• An end date, if applicable

Dates establish a timeline and show the agreement was deliberate, not an afterthought.

3. Identify Both Parties Clearly

Use full names (or at least the names you consistently use with each other). Vague references like "both of us" without identifying who "us" is weakens the document.

4. Define Key Terms

If your agreement uses terms that could be interpreted different ways, define them. For example:

"'Meeting' refers to an in-person visit lasting at least two hours. Phone or video calls are not considered meetings for the purposes of this agreement."

This might feel overly precise for a casual arrangement, but precision prevents disputes.

5. Make Terms Mutual Where Possible

Agreements that impose obligations on only one party are more likely to be seen as unfair or coercive. Where possible, frame terms as mutual commitments.

One-sided: "Party B will maintain exclusivity." Mutual: "Both parties agree to maintain exclusivity for the duration of this arrangement."

Even if the arrangement isn't perfectly symmetrical, showing that both people have responsibilities strengthens the document.

6. Include an Exit Clause

An agreement without an exit clause can be interpreted as either permanent (unreasonable) or meaningless (easily abandoned). Include clear terms for how either party can end the arrangement.

See how to write an exit clause for detailed guidance.

7. Add a Severability Clause

A severability clause says that if one part of the agreement is found to be unenforceable, the rest of it still stands. This is standard in formal contracts and easy to include:

"If any provision of this agreement is found to be invalid or unenforceable, the remaining provisions will continue in full force and effect."

8. Document Agreement and Consent

Both parties should:

• Sign and date the agreement (digital signatures count)
• Keep a copy
• Acknowledge in writing that they entered the agreement voluntarily

Example acknowledgment:

"By signing below, both parties confirm that they have read this agreement, understand its terms, and are entering into it voluntarily and without coercion."

This directly addresses one of the most common challenges to informal agreements — the claim that one party didn't know what they were agreeing to.

9. Avoid Illegal or Legally Risky Terms

This should go without saying, but: don't include terms that could be interpreted as illegal. This includes anything that ties financial support directly to specific intimate acts, terms that restrict someone's legal rights, or non-compete clauses between individuals in a personal relationship.

If you're unsure whether a term crosses a legal line, consult an attorney. See keeping arrangements legal and when to hire a lawyer.

10. Build in a Review Process

Include a specific process for revisiting and updating the agreement. This shows the arrangement is a living document, not a one-time mandate.

"Both parties agree to review and, if necessary, update this agreement every 90 days. Updates require the written agreement of both parties."

For more on this, see how to handle amendments and updates.

What Your Agreement Should Cover

At minimum, include sections for:

• Purpose and nature of the arrangement
• Financial terms (if applicable)
• Communication expectations
• Confidentiality
• Boundaries and limitations
• Duration and review schedule
• Exit clause
• Signatures and date

For a complete structural guide, see how to structure a casual agreement.

The Enforceability Spectrum

Think of enforceability as a spectrum rather than a binary:

Most casual arrangements will fall somewhere in the middle. The goal isn't to reach the level of a formal contract — it's to move as far up this spectrum as feels appropriate for your situation.

A Realistic Disclaimer

This article is for informational purposes only and does not constitute legal advice. Casual agreements between individuals exist in a legal gray area. No amount of careful writing guarantees enforceability. If you need an agreement that will hold up in court, consult a licensed attorney in your jurisdiction.

What a well-written casual agreement does guarantee is that both people are on the same page. And honestly? That's the real value. Most disputes in casual arrangements aren't resolved by judges — they're resolved (or prevented) by having clear, written terms that both people understood from the start.

For more on the legal foundations of casual agreements, visit the enforceability basics hub.