Can I sue someone for unpaid debt without a contract?
Yes. The law gives you alternatives to a written contract. Even without a formal contract, three legal theories can win the case: (1) the borrower got money or value from you and it would be unfair for them to keep it without paying (the law calls this 'unjust enrichment'); (2) they made a promise, you relied on it, and you got hurt as a result ('promissory estoppel'); (3) your prior transactions with them established a pattern ('course of dealing'). The proof is harder than a written-contract case, but the recovery is the same. The backbone: documentation of the transfer + the borrower's understanding of the obligation.
What can you recover without a contract?
Four legal theories work even without a signed agreement.
Unjust enrichment
The borrower got money or services from you and it would be unfair for them to keep it without paying. You don't need to have made an explicit agreement — just show they unfairly kept something of value. The most common theory in informal cases.
Promissory estoppel
The borrower made a clear promise; you relied on it; you got hurt as a result. Even without a formal contract, a broken promise creates legal responsibility. Useful when verbal agreements are disputed.
Course of dealing
Your prior transactions with this person establish a pattern. Repeated similar exchanges with consistent repayment terms create an unwritten 'implied contract.' Each new transaction is treated as following the established pattern.
Fair value of services (quantum meruit)
If you provided services instead of money, you can recover the reasonable value of those services. Common for freelance work without a written contract. Courts use typical industry rates to set the value.
How much can you claim?
The amount transferred plus pre-judgment interest plus filing fees.
Original amount transferred
Bank transfer record, business invoice, or receipts for services rendered. The transfer itself is the foundation.
Pre-judgment interest
State legal rate (7 to 10 percent per year) running from the transfer date or first demand.
Filing fees, post-judgment interest
Filing fee (often higher for larger claims), service-of-process cost, post-judgment interest until paid.
$8,000 transfer plus pre-judgment interest, plus filing fee.
Send a demand letter first.
Demand letters work especially well for no-contract cases because the alternative theories (unjust enrichment, promissory estoppel) are less familiar to most borrowers. The letter educates them about the legal exposure.
- Detailed timeline of the transfer or services
- Bank record or invoice
- Texts, emails, or witness testimony establishing the borrower's understanding
- The legal theory you're relying on (unjust enrichment, promissory estoppel)
- Pre-judgment interest calculation
- A 14-day deadline before you file
- Sent certified mail
On August 14, 2024, I transferred $8,000 to you to cover the down payment on your new car. We did not have a written contract, but our text exchange (attached) establishes your understanding that the money was a loan and would be repaid as soon as your tax refund arrived in 2025. Your tax refund arrived in May 2025; you have not repaid any portion.
Under the doctrines of unjust enrichment and promissory estoppel, you are obligated to repay. I demand within fourteen (14) days:
- Repayment of $8,000 in advance;
- Pre-judgment interest at 10 percent per year for 1.5 years ($600).
Total demand: $8,600.00. If unresolved, I will file in Small Claims Court.
How to file a no-contract case.
Four steps. Stitching together evidence under a recognized legal theory is the case.
Identify the legal theory
Unjust enrichment (most common): the borrower received money and it would be unfair to keep without paying. Promissory estoppel: they promised to repay and you relied on it. Course of dealing: prior transactions establish the pattern.
Document everything
Bank records, texts, emails, witness statements. Even casual references to the money in subsequent communications support the case.
Send certified-mail demand
Cite the legal theory specifically. Many borrowers settle once they realize the law has names for what they did.
File in small claims
If demand fails, file. Filing fees usually run $30 to $200. Lead with the theory and the documented transfer.
Collecting on a no-contract judgment.
Money judgments enforce via judgment lien, bank levy, and writ of execution. No-contract judgments enforce identically to written-contract judgments once entered.
What evidence do you need without a contract?
Bank records, texts, and circumstantial evidence under unjust-enrichment theory.
Outgoing wire to Jordan Borrower, account 5678.
Memo: 'Down payment advance per text — repay 2025'
Confirmed 08/15/2024.
Unjust enrichment doctrine
A person who is unjustly enriched at the expense of another is subject to liability in restitution.
Unjust enrichment may arise from the conferring of a benefit by mistake, fraud, or other circumstance making it unjust for the recipient to retain.
Borrower received $8,000, used it for car, never repaid. Retention is unjust without payment.
Common borrower defenses, with rebuttals.
Three arguments cover most no-contract cases.
Keep it simple. Organized records, clear timelines, and solid evidence are your best defense.
How much do lenders actually recover?
No-contract cases recover when documentation is strong.
Partial recovery. Court awards portion when documentation is weak or competing theories complicate.
Full principal + interest. Most common when bank records and borrower's own words establish the unjust enrichment.
Cap-of-court awards. Larger no-contract advances with strong documentation push to cap.
Better evidence. Better prep. Better outcome. Your documentation makes the difference.
What are the alternatives to small claims?
Demand letter is the lowest-friction path. Mediation works for relationship-preservation cases.
Demand letter alone
Free, educationalWhen it fits: documented advance with the borrower's understanding. Many borrowers settle once they understand the legal theories.
Tradeoff: no enforcement if borrower ignores.
Mediation
Preserve relationshipsWhen it fits: personal relationships you want to maintain. Community mediation centers offer services for $50 to $200.
Tradeoff: no enforcement; only effective if borrower participates.
Small claims (this guide)
Reliable enforced recoveryWhen it fits: demand letter failed. Damages within your state's cap. The unjust-enrichment theory applies.
Tradeoff: 30 to 90 day timeline.
Recover the advance.
Most no-contract cases settle once a demand letter cites the legal theory. Our generator builds yours in under two minutes.
Illustrative. Larger advances push to small-claims cap.
Frequently asked.
The questions lenders actually ask before filing. Email support if yours isn’t here.
Can I sue someone for money I gave them without a contract?
Yes. Unjust enrichment, promissory estoppel, and quantum meruit are alternative legal theories that don't require a formal contract. The borrower's understanding of the obligation (from texts, emails, or course of dealing) is the central evidence.
What is unjust enrichment?
A common-law doctrine that prevents a person from keeping money or benefits received at another's expense when retention would be unfair. Most state courts recognize it. Common in informal financial relationships.
What is promissory estoppel?
A doctrine that enforces promises when the promisee reasonably relied on them to their detriment. Even without a formal contract, the broken promise creates liability for the resulting loss.
How do I prove unjust enrichment?
Bank record showing the transfer plus evidence of the borrower's understanding (texts, emails, witness testimony). The borrower's subsequent retention of the benefit without payment establishes 'unjust' retention.
What if I provided services instead of money?
Quantum meruit applies. You can recover the reasonable value of services rendered. Courts use industry rates to set value. Common for freelance work without written contracts.
How long do I have to sue?
Unjust enrichment and quasi-contract claims usually run 3 to 4 years. Promissory estoppel runs on the underlying promise's clock (often 2 to 4 years). State law varies; check your specific deadline.
Will the court take this seriously without a contract?
Yes. Unjust-enrichment cases are common in small-claims and standard in higher courts too. The theories are well-established. The challenge is documentation, not legal recognition.