Can Copying Files to a USB Before Leaving Your Job Lead to Criminal Charges? | Post-Resignation Confidentiality Obligations in Korea
Changing jobs in Korea? Copying work files to a USB or personal cloud before resigning could expose you to criminal prosecution - even if those files don't qualify as "trade secrets." Sugar Square explains the legal boundaries every employee and employer should know under Korean law.
Apr 12, 2026
1. The Scenario: "I Just Took What I Made"
It happens more often than you'd think.
An employee resigns after years of service. Before leaving, they copy project files, client lists, or design documents onto a personal USB drive. Their reasoning is simple: "I created these - they're basically mine."
But under Korean law, this assumption can lead to serious criminal liability.
Supreme Court rulings have made it clear that the act of taking files itself - not just using them later - can constitute a completed criminal offense at the moment of removal.
2. Two Legal Tracks
Korean law provides two separate criminal frameworks for prosecuting unauthorized file removal. This is a critical distinction that many people miss.
Track 1: Unfair Competition Prevention And Trade Secret Protection Act (부정경쟁방지 및 영업비밀보호에 관한 법률)
This applies when the information qualifies as a "trade secret" (영업비밀).
The three requirements are:
- Non-public nature (비공지성): Not publicly known or readily accessible
- Economic value (경제적 유용성): Provides a competitive advantage
- Secrecy management (비밀관리성): Managed and marked as confidential
Penalties: Up to 10 years imprisonment or KRW 500 million fine for domestic cases; up to 15 years or KRW 1.5 billion for international cases (UCPA Art. 18)
👉 For a detailed breakdown of these three requirements, see: Is a YouTuber's Ad Rate a Legally Protected Trade Secret?
Track 2: Occupational Breach of Trust (업무상배임죄, Criminal Act Art. 356)
This applies even when the information does NOT qualify as a trade secret, as long as it constitutes a "major business asset" (영업상 주요한 자산).
The Supreme Court has consistently held:
"Even if the data does not constitute a trade secret, if it is not publicly available, the company invested significant time, effort, and cost in its development, and its use would yield a competitive advantage, the unauthorized removal constitutes Occupational Breach of Trust." (Supreme Court, April 24, 2008, Case No. 2006Do9089)
Penalties: Up to 10 years imprisonment or KRW 30 million fine (Criminal Act Art. 356)
‼️ Where the gain from the breach exceeds KRW 500 million, the Act on the Aggravated Punishment of Specific Economic Crimes (특정경제범죄 가중처벌 등에 관한 법률) Art. 3 imposes enhanced penalties: KRW 500 million to 5 billion → minimum 3 years imprisonment; over KRW 5 billion → life imprisonment or minimum 5 years.
👉 For a real-world case analysis, see: Can You Be Punished for Taking Company Files Even If They're Not Trade Secrets?
3. The Critical Timeline: When Does the Crime "Complete"?
Understanding when the offense is legally completed (기수시기) is essential. It determines what actions create liability and what defenses remain available.
Scenario A - Unauthorized removal while employed
The offense is completed at the moment of removal. (Supreme Court, April 24, 2008, Case No. 2006Do9089)
Scenario B - Legitimate access during employment, failure to return/delete upon resignation
The offense is completed at the time of resignation. (Same ruling)
Scenario C - Actions after resignation
Once you have left the company, you are generally no longer in a fiduciary position. Post-resignation use of already-removed files does not create a new breach of trust charge — though it may still constitute a separate UCPA violation. However, exceptions exist: if the employee continues to perform specific tasks entrusted by the former employer after resignation, or if the circumstances of resignation indicate that the fiduciary relationship has not yet been severed, liability may still attach.
‼️ The most critical moment is the day you resign. If you still possess company files at that point and fail to return or delete them, the criminal offense is complete - regardless of whether you ever actually use them.
4. Supreme Court's Clarification: The "Major Business Asset" Standard
In a 2011 ruling, the Supreme Court clarified the standard for what constitutes a "major business asset" under Occupational Breach of Trust:
"For unauthorized file removal to constitute Occupational Breach of Trust, the data need not necessarily qualify as a trade secret, but must at minimum be: (1) not publicly disclosed to the general public, such that it cannot ordinarily be obtained without going through the holder; (2) developed with significant investment of time, effort, and cost by the holder; and (3) capable of yielding a competitive advantage through its use." (Supreme Court, July 14, 2011, Case No. 2010Do3043)
This ruling means not every internal document qualifies. Routine administrative files or publicly available templates would likely not meet this standard.
5. What About Your NDA and Non-Compete?
Many employees sign confidentiality agreements and non-compete clauses upon hiring or resignation.
Key points to understand:
- NDAs survive termination.
Your duty not to disclose confidential information continues for the period specified in the agreement.
- Non-compete clauses are not automatically enforceable.
Korean courts evaluate non-compete agreements based on the following comprehensive factors:
- Whether the employer has a legitimate interest worth protecting
- The employee's position and role prior to resignation
- The scope, duration, and geographic area of the non-compete restriction
- Whether adequate compensation was provided to the employee
- The circumstances of the employee's resignation
- Public interest considerations
👉 For a comprehensive analysis of non-compete enforceability, see: Non-Compete Agreements: Can They Actually Stop You?
- Signing an NDA under duress
(e.g., "sign or we withhold your severance") may render the agreement voidable under the Korean Civil Act (민법) Art. 110. The following requirements must all be met:
- Existence of a coercive act (강박행위)
- The coercion induced fear in the other party
- The declaration of intent was made as a result of that fear
‼️ The right to rescind is subject to a limitation period (제척기간): 3 years from the date the coercion could be identified, and 10 years from the date of the legal act.
- Directors' confidentiality obligations apply regardless of NDA.
Under the Korean Commercial Act (상법) Art. 382-4, directors have a statutory duty not to disclose business secrets learned through their duties, both during and after their term of office. This obligation applies irrespective of whether an NDA was signed.
☑️ Sugar Square Check Point
For Employees Leaving a Job:
- Delete all company files from personal devices, USB drives, cloud storage, and personal email before your last day.
- Do not assume "I created it, so it's mine." If the company invested resources in its development, it may be their asset.
- Request a written confirmation of file deletion/return from your employer.
- Review your NDA and non-compete before accepting a new position in the same industry.
- Consult a lawyer before resignation if you are unsure about what you can and cannot take.
For Employers Protecting Assets:
- Implement a standardized offboarding process that includes digital forensic verification of file deletion.
- Maintain clear access logs and classification of sensitive information.
- Update NDAs and security pledges to reflect current digital realities (cloud, personal devices, messaging apps).
- Act quickly - evidence of unauthorized file removal is most effectively preserved through prompt forensic investigation.
👀 More from Sugar Square on Trade Secret & Employment
Sugar Square Law Firm provides comprehensive legal solutions for trade secret disputes, employee off-boarding compliance, NDA enforcement, and criminal defense in occupational breach of trust cases.
[Contact Us]
- Tel: 02-563-5877
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- Email: sugar@sugar.legal
- 2F, Baekam Art Center Annex, 7 Teheran-ro 113-gil, Gangnam-gu, Seoul, Korea
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