Civil Litigation

Unjust Enrichment Claim Lawyer

Unjust Enrichment Claim Lawyer | What you need to prove, and how to get your money back

Summary

Unjust enrichment occurs when a person receives a benefit — money, property, or the use of something of value — without any legal basis, causing a corresponding loss to another person. Under Korean law, the person who benefited must return the gain, and in some cases pay interest, once the claimant proves the benefit, the loss, the causal link between them, and the absence of legal grounds (민법 제741조). These disputes range from a simple mistaken bank transfer to complex disputes over rent, deposits, overpaid wages, or benefits received under a contract that is later found void or rescinded.

Civil · Money Disputes Related law: Civil Act (민법) Contract & Restitution

Unjust Enrichment Claim | What You Must Prove to Win an Unjust Enrichment Claim

A claim for return of unjust enrichment succeeds only if four elements are established under Article 741 of the Civil Act (민법 제741조). Courts examine each element separately, and a case often turns on just one of them — usually whether there was truly 'no legal cause.'

Element 1

The other party received a benefit
The defendant must have obtained something of economic value — money, property, a discharged debt, or the use of an asset. This is usually the easiest element to prove with bank records, contracts, or registry documents.

Element 2

You suffered a corresponding loss
Your loss does not need to be identical in form to the defendant's gain, but there must be a recognizable link, such as money leaving your account or property being used without your consent. Courts look at whether the loss and the gain stem from the same underlying event.

Element 3

Causal connection between the gain and the loss
The benefit received by the defendant and the loss suffered by the claimant must arise from the same transaction or event. Where money passed through several parties, tracing this causal link is often the most contested part of the case.

Element 4 — usually decisive

No legal ground for the benefit
This is where most litigation is concentrated. If a contract, statute, or prior judgment justified the transfer, there is no unjust enrichment even if the outcome feels unfair. Typical scenarios include a contract later declared void or rescinded, an overpayment made by mistake, or performance rendered under a contract that never actually existed (민법 제741조).

Exceptions That Can Bar Recovery

Even if all four elements are met, the law denies a refund in certain situations: if you paid knowing there was no legal obligation, you generally cannot demand it back (민법 제742조), and if the payment was made to satisfy an obligation contrary to good morals or social order, the law may bar you from recovering it entirely (민법 제746조). These provisions are frequently raised as defenses, so anticipating them early shapes how the claim should be framed.

Unjust Enrichment Claim | Evidence and Strategy in Common Unjust Enrichment Scenarios

Unjust enrichment claims look simple on paper but often involve difficult evidentiary questions about intent, tracing of funds, and the scope of what must be returned. The following scenarios come up most often in practice.

Mistaken bank transfers and misdirected payments

When money is sent to the wrong account, the recipient generally must return it even if they did nothing wrong, because holding money transferred by mistake without legal cause is itself the enrichment (민법 제741조). Disputes usually arise when the recipient has already spent the funds or claims they were owed the money for an unrelated reason, which shifts the fight to proving what the payment was actually for.

Void or rescinded contracts and restitution of what was exchanged

When a contract is voided — for example due to fraud, duress, or a party lacking capacity — both sides must return what they received under it, since performance rendered under a nonexistent legal relationship becomes unjust enrichment (민법 제741조). The contested issue is often not whether restitution is owed, but how to value benefits that cannot be returned in kind, such as services already performed or property that has since decreased in value.

Overpaid wages, rent, and deposit disputes

Employers seeking to recover overpaid wages, or tenants and landlords disputing deposit balances after a lease ends, frequently rely on unjust enrichment when there is no separate contractual clause covering the overpayment. These cases often turn on documentation — pay stubs, lease terms, and account statements — to establish the exact amount that exceeds what was legally owed.

Good faith vs. bad faith recipients and the scope of what must be returned

How much must be returned depends on whether the recipient knew, at the time, that they had no right to the benefit. A recipient acting in good faith only has to return the benefit as it currently exists, while a recipient acting in bad faith must return the full original benefit plus interest (민법 제748조). Proving the recipient's state of mind at the time of receipt is often the deciding factor in how much is ultimately recovered.

Unjust Enrichment Claim | From Initial Consultation to Final Judgment or Settlement

Fact-gathering and legal review
The lawyer reviews bank records, contracts, messages, and any other documentation to identify which of the four elements are strong and which will be contested, and estimates the amount that can realistically be claimed.

Demand and pre-litigation negotiation
A formal demand letter is often sent first, both to preserve evidence of the claim and to test whether the other side will return the benefit voluntarily, which can resolve the matter without a lawsuit.

Provisional attachment, if needed
If there is a risk the other party will dispose of assets before judgment, a provisional attachment (가압류) on their bank accounts or real estate can be filed to secure future enforcement.

Filing the lawsuit and litigation
The complaint sets out the benefit, the loss, the causal link, and the absence of legal cause, supported by documentary evidence; the case then proceeds through pleadings, evidence submission, and hearings before the civil court.

Judgment, settlement, or enforcement
Many cases settle at some point during litigation once the evidence is laid out; if the case goes to judgment and the other side still does not pay, the judgment can be enforced against their assets.

Unjust Enrichment Claim | How Legal Fees Are Calculated for These Cases

Retainer fee
Typically set based on the claimed amount and the complexity of tracing the benefit and loss, rather than a flat rate, since evidentiary difficulty varies widely between a simple mistaken transfer and a multi-party contract dispute.

Contingency / success fee
Often structured as a percentage of the amount actually recovered, whether through settlement, judgment, or enforcement, and is discussed and agreed with the client before filing.

Court costs and stamp duty
Filing fees and stamp duty are calculated based on the amount claimed in the complaint and are paid separately from attorney fees, in accordance with court fee schedules.

Provisional attachment costs
If a provisional attachment is necessary to secure the claim, additional costs apply for the application and any security deposit or bond required by the court.

Enforcement costs
If the losing party does not pay voluntarily after judgment, separate costs arise for compulsory enforcement procedures against their bank accounts, wages, or real estate.

※ Costs vary depending on case complexity and specific circumstances; exact fees will be provided during consultation. No specific outcome is guaranteed.

Unjust Enrichment Claim | Self-Check Before You File

1️⃣ For the Party Seeking Return of the Benefit (Claimant)

Can you show a specific benefit the other party received — a sum of money, an asset, or a discharged debt?
Can you document your own corresponding loss with bank records, receipts, or contracts?
Is there a clear link between what you lost and what they gained, or did the money pass through several parties?
Was there ever a contract, court order, or statute that could justify the transfer, even one that was later voided?
Did you make the payment knowing you had no legal obligation to do so?

2️⃣ For the Party Being Asked to Return a Benefit (Respondent)

Did you have a contract, invoice, or prior agreement that justified receiving the payment?
Have you already spent or consumed the benefit, and if so, can you show you acted in good faith at the time?
Is there evidence the claimant knew there was no obligation when they paid, which could bar their claim (민법 제742조)?
Could the underlying transaction be considered contrary to good morals or social order, which may limit the claimant's right to recover (민법 제746조)?

3️⃣ Before Filing a Lawsuit

Have you sent a formal demand and kept a record of the other side's response, or refusal to respond?
Is there a real risk the other party will transfer or hide assets before a judgment is enforced?
Have you calculated the exact amount claimed, including any interest for the period the benefit was withheld?
Have you gathered all bank statements, contracts, and correspondence relevant to the transaction?

Frequently Asked Questions

Q. I accidentally sent money to the wrong bank account. Do I have to sue to get it back?

A. Not necessarily at first — many banks can assist with return requests for mistaken transfers, and a formal demand letter often resolves the matter without litigation. If the recipient refuses to return the funds despite having no legal basis to keep them, a lawsuit for unjust enrichment can be filed (민법 제741조).

Q. How long do I have to file an unjust enrichment claim?

A. Claims for return of unjust enrichment are generally subject to the ordinary civil statute of limitations, which is ten years from the time the right could be exercised under the Civil Act, though shorter periods can apply depending on the underlying transaction. It is best to have a lawyer review the specific facts, since related claims such as tort damages can have much shorter deadlines.

Q. What is the difference between an unjust enrichment claim and a tort damages claim?

A. An unjust enrichment claim focuses on returning a benefit received without legal cause, while a tort claim focuses on compensating a wrongful act that caused damage; the two can sometimes be pursued together for the same facts, but they have different elements and different limitation periods. Which framing is stronger depends on whether the case is easier to prove as a lack of legal ground or as a breach of duty.

Q. Does the other person have to pay interest on top of returning the money?

A. Yes, in many cases. If the recipient acted in bad faith, they must return the benefit along with interest calculated from the time they received it, while a good faith recipient's liability may be limited to what remains of the benefit at the time the claim is made (민법 제748조).

Q. Can I recover unjust enrichment if the underlying contract was illegal?

A. It depends on the nature of the illegality. If the payment was made to fulfill an obligation that violates good morals or social order, the law can bar the person who paid from recovering it, even though the recipient technically has no legal ground to keep it (민법 제746조).

Q. My landlord is refusing to return part of my deposit after unrelated deductions. Is this an unjust enrichment case?

A. It can be, if the landlord withheld amounts not authorized by the lease or by law, since keeping money beyond what is legally owed without a valid basis fits the elements of unjust enrichment (민법 제741조). These disputes often depend heavily on what the lease agreement specifies about deductions, so reviewing the contract terms closely is an important first step.

Q. What evidence should I gather before consulting a civil litigation lawyer?

A. Bank statements showing the transfer or payment, any related contracts or agreements, written communication with the other party, and a timeline of events are the most useful starting materials. A civil litigation lawyer can identify early which of the four legal elements are strongest in your case and which need more supporting evidence.

Q. Can I still file a claim if I already sent several demand messages and got no response?

A. Yes — unanswered demand letters do not bar a lawsuit and can actually serve as evidence that you attempted to resolve the matter before litigation. Keeping records of all such communications strengthens the claim when it eventually goes before the court.

Q. Is a provisional attachment necessary in every unjust enrichment case?

A. No, it is only recommended when there is a genuine risk the other party will transfer, hide, or spend down assets before a judgment can be enforced. Many straightforward cases proceed directly to litigation without this additional step.

Q. Someone at my company received a duplicate payment by mistake. Can the company recover it directly, or must it go through HR procedures first?

A. Both paths can be pursued, but if internal recovery through payroll adjustment is not possible or the employee has left the company, a civil claim for unjust enrichment is available since the overpayment itself constitutes a benefit received without legal cause. Consulting a civil litigation lawyer early helps determine whether payroll offset rules or a court claim is the faster route.

Official References

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