A foreign technology supplier collaborates with a Korean manufacturer, shares product drawings under a confidentiality agreement, and later sees a similar Korean patent filing. The business reaction is immediate: sue for breach of the NDA, claim the agreed penalty, and argue that similarity proves misuse. In practice, NDA breach litigation in Korea is more demanding than that.

Korean courts do enforce confidentiality agreements. They also recognize contractual penalties and liquidated damages clauses when properly drafted. But recent Korean litigation involving a foreign company and a Korean logistics automation business shows a recurring problem: external similarity between products, drawings, or patents may not be enough unless the plaintiff proves what information was protected, how it was delivered, and how the defendant actually used it.

This matters for foreign companies because Korea-facing partnerships often require early disclosure. Joint development projects, distributor onboarding, OEM supply talks, software implementation, clinical collaboration, and M&A diligence all involve confidential material moving across borders. If the NDA file is loose, the company may discover too late that the litigation record does not match the commercial story.

NDA Breach Litigation in Korea Starts With the Protected Information

The first question in NDA breach litigation in Korea is not whether the defendant's later product looks similar. The first question is what information the NDA actually protected. Korean courts will examine the contract language, the nature of the information, the delivery channel, and whether the information was already public or independently available.

This is different from a broad business assumption that "everything discussed was confidential." A plaintiff should be able to identify the specific confidential information: drawings, source code, formulas, cost data, customer lists, process parameters, test reports, pricing models, supplier terms, or business plans. The more precise the definition, the easier it is to prove breach.

The Civil Act provides the basic framework for contract liability. Under Civil Act Article 390, a party that fails to perform its obligation may be liable for damages unless non-performance occurred without intent or negligence. For an NDA, the relevant obligation is usually non-use, non-disclosure, return or destruction of materials, and sometimes restrictions on reverse engineering or patent filing.

Where the information also qualifies as a trade secret, the Unfair Competition Prevention and Trade Secret Protection Act becomes important. Article 2 defines a trade secret as information that is not publicly known, has independent economic value, and has been managed as secret. Article 10 provides a basis for injunctions against trade secret infringement, and Article 11 supports damages claims. But an NDA claim and a trade secret claim are not identical. Contractual confidentiality can protect information that may not satisfy every trade secret element, while trade secret law can provide stronger remedies where the statutory elements are met.

Foreign companies should therefore plead and prove the case in layers. The contract claim should identify the NDA obligation and the specific protected material. The trade secret claim, if available, should explain non-public status, economic value, secrecy management, acquisition, use, and harm. Treating the NDA as a general label for all business frustration is a weak start.

NDA Breach Litigation in Korea Requires Proof of Delivery and Access

The second issue is whether the defendant actually received the protected information through a covered channel. In many disputes, the foreign plaintiff has strong commercial suspicion but weak delivery evidence. A brochure was exchanged, engineers visited a site, a sales employee viewed a website, or technical discussions occurred in meetings. Those facts may matter, but they must connect to the specific information later alleged to have been misused.

For example, assume a US robotics company gives a Korean integrator a password-protected motor-control specification during a pilot project. Two years later, the Korean integrator files a patent with similar control logic. The plaintiff's evidence should show the version of the specification, who received it, when it was accessed, whether it was marked confidential, whether the patent inventors had access, and which patent claims reflect the protected logic.

By contrast, if the plaintiff can show only that the defendant once visited a public website or received a marketing brochure, the claim becomes harder. Public-facing materials may still contain useful business information, but the plaintiff must explain why the disputed information was non-public or contractually restricted. Korean courts are unlikely to infer breach from a single access record without more.

The Civil Procedure Act places the burden of proof on the party asserting the facts necessary for its claim. In practical terms, the plaintiff must prove the existence of the NDA, the protected information, the defendant's access, breach, causation, and damages or contractual penalty trigger. The defendant does not need to disprove every suspicion if the plaintiff cannot establish the chain.

This is why data discipline matters before a dispute begins. Foreign companies should maintain clean transmission records: data-room logs, email delivery records, meeting minutes, version histories, confidentiality legends, recipient lists, and return or destruction confirmations. In litigation, those records often matter more than polished witness statements.

Similarity Is Evidence, Not the Whole Case

Similarity can be powerful evidence in an NDA case, especially when the protected information is highly technical and not independently discoverable. But similarity is rarely enough by itself. Korean courts will ask whether the similarity could come from public standards, common engineering constraints, independent development, reverse engineering, prior art, customer specifications, or ordinary market practice.

Consider a German packaging equipment company that alleges a Korean partner copied a component design. The two machines look similar from the outside, and both use comparable guide rails. If those guide rails are standard in the industry, external similarity may prove little. The plaintiff would need to show that the copied feature came from confidential drawings or know-how, not from public catalogs or engineering necessity.

The analysis becomes more persuasive when the plaintiff can identify internal fingerprints. These may include unusual tolerances, non-obvious design choices, hidden process steps, identical errors, matching file metadata, copied variable names, document revision codes, or access shortly before a competing filing. A patent drawing that resembles a product may support suspicion. A patent claim that tracks a confidential test method disclosed in a restricted technical memorandum is stronger.

For defendants, the lesson is equally clear. A Korean company accused by a foreign partner should not rely only on denial. It should preserve and present independent development records: R&D notebooks, prior art searches, supplier drawings, employee assignment records, lab notebooks, Git history, prototype timelines, patent attorney communications where producible, and public source materials. A credible independent development story can defeat the inference that similarity means misuse.

Contractual Penalties and Civil Act Article 398

Many cross-border NDAs include a fixed penalty for breach. The amount may be designed to avoid difficult damages proof, deter leakage, or create leverage in settlement. Korean law allows parties to agree in advance on damages, but Article 398 of the Civil Act is critical.

Civil Act Article 398 permits agreed damages for non-performance and allows a court to reduce the amount if it is unduly excessive. A clause requiring $1.1 million for any confidentiality breach may be enforceable in some circumstances, but the court will look at proportionality, the nature of the breach, the commercial value of the information, the parties' bargaining position, actual harm, and whether the breach was serious.

Foreign companies should avoid drafting a penalty clause as a blunt threat. A better clause distinguishes categories of breach. Unauthorized disclosure of source code, formula data, customer pricing, or non-public engineering drawings can carry a higher agreed amount. Minor administrative breaches, delayed return of documents, or accidental disclosure that is quickly contained may justify a lower amount or a cure mechanism.

The clause should also state whether the agreed amount is exclusive or whether the injured party can seek additional damages, injunctions, return of materials, deletion certification, and attorney-fee recovery if available. If the NDA is part of a larger supply, license, employment, or joint development agreement, the remedies should be coordinated across documents.

One practical drafting point is often missed: a penalty clause does not eliminate the need to prove breach. If the plaintiff cannot show that protected information was delivered and misused, the penalty never activates. The agreed amount solves only part of the problem. It does not replace the evidence chain.

Trade Secret Claims, Injunctions, and Criminal Pressure

An NDA lawsuit may be only one part of the strategy. If the facts involve technical information, source code, product formulas, manufacturing processes, or customer data, a trade secret claim under the Unfair Competition Prevention and Trade Secret Protection Act may be more powerful.

Article 2 of that Act requires secrecy management. This means the company must show that it treated the information as confidential before the dispute. Password controls, access limits, employee policies, document labels, clean-room protocols, need-to-know sharing, and exit certifications can all support this element. A plaintiff that freely circulated the same file without controls may struggle to prove trade secret status.

Article 10 can support injunctive relief where trade secret infringement is threatened or ongoing. This matters when the defendant is about to launch a product, file regulatory materials, submit a bid, or disclose the information to another partner. Waiting until final judgment may not be commercially realistic.

Criminal complaints are also possible in serious trade secret cases. They can create investigation pressure and may help preserve evidence. But they should be used carefully. Korean prosecutors will expect a concrete explanation of the protected information, acquisition route, misuse, and intent. A criminal filing based only on commercial suspicion can weaken settlement posture if it appears overreaching.

For foreign executives, the decision tree is practical. If the dispute is mainly about violation of a contractual use restriction, the NDA claim may be central. If the dispute involves valuable non-public technical or business information managed as secret, trade secret remedies should be considered. If the defendant is dissipating assets or likely to ignore a judgment, provisional attachment may also belong in the litigation plan.

Evidence Strategy Before Filing an NDA Claim

The strongest NDA cases are built before the complaint is filed. Korean litigation is document-centered, and judges will expect a coherent record. A foreign plaintiff should assemble a timeline that connects contract, disclosure, access, conduct, breach, and harm.

Start with the NDA itself. Confirm the parties, effective date, governing law, forum, definition of confidential information, permitted purpose, non-use clause, non-disclosure clause, return obligations, survival period, affiliates, employees, subcontractors, and remedies. If Korean law applies, align the claim with Civil Act Articles 390 and 398. If the forum is arbitration, check whether emergency or interim relief is available.

Next, identify the exact materials disclosed. Use exhibit-level precision. Instead of saying "technical information," list the file name, version, date, author, recipient, and confidential marking. If materials were shared in meetings, preserve agendas, attendance records, slide decks, follow-up emails, and translation records. If the information was uploaded to a data room, export the access logs before retention periods expire.

Then map suspected use. Compare the protected material with the defendant's patent filings, product manuals, regulatory filings, marketing materials, bids, source code, or customer proposals. The comparison should separate public similarities from confidential features. If a patent attorney, engineer, forensic specialist, or industry expert is needed, involve them early.

Finally, quantify the remedy. If claiming a contractual penalty, identify the clause and the event that triggered it. If claiming actual damages, calculate lost profits, lost bids, price erosion, development costs, or reasonable royalty in USD. If seeking an injunction, show urgency and likely irreparable commercial harm.

Practical Tips for Foreign Companies

Define confidential information specifically. Attach schedules, categories, file names, and examples instead of relying only on broad boilerplate.
Use purpose restrictions. State that information may be used only for the identified project, tender, diligence review, or supply discussion.
Track delivery and access. Keep data-room logs, email records, meeting minutes, recipient lists, and version histories.
Mark and manage sensitive files. Confidential labels, password controls, and need-to-know permissions help both contract and trade secret claims.
Do not rely on similarity alone. Build the evidence chain from protected information to access to use.
Draft penalty clauses with proportionality. Article 398 reduction risk is lower when the amount matches the commercial importance of the obligation.
Preserve independent development evidence if accused. Defendants should secure R&D timelines, prior art, public sources, and internal records quickly.
Coordinate NDA claims with trade secret remedies. Injunctions, damages, criminal complaints, and provisional attachment may all be relevant.
Check governing law and forum before filing. Korean court litigation, KCAB arbitration, or foreign proceedings can change available interim measures.
Prepare translations carefully. Korean courts need precise translations of foreign-language NDAs, technical exhibits, and correspondence.

Conclusion

NDA breach litigation in Korea rewards disciplined evidence work. A foreign company must prove more than suspicion, disappointment, or product similarity. It needs a clear definition of protected information, a record of disclosure and access, a persuasive explanation of misuse, and a remedy theory that fits Korean law.

The best protection begins before the first file is shared. Strong NDAs, controlled data rooms, confidentiality markings, access logs, and proportional penalty clauses make later enforcement much easier. Korea Business Hub assists foreign companies with Korean contract disputes, NDA enforcement, trade secret protection, provisional remedies, and litigation strategy when confidential information is at risk.

NDA Breach Litigation in Korea: Guide for Foreign Companies