📂HR & Labor⏱2 min read📊Advanced🔗6 related

What is an unfair labor practice?

In one line
Employer conduct that obstructs workers’ three labor rights. Retaliatory treatment, yellow-dog contracts, refusal of collective bargaining, and control or interference are prohibited by law.
⚡ Summary in 3 lines
  • Retaliatory treatment, yellow-dog contracts, refusal to bargain, and control or interference
  • A field manager's words and actions become the company's liability
  • Document the reasons and criteria for personnel actions

The focus in judging an unfair labor practice is less “was the action justified?” than “did the action carry an intent tied to union activity?” The same transfer is a legitimate exercise of management authority if documents show it was under review for six months over poor performance, but if the approval goes up ten days after a union registration filing, you stand where your motive will be questioned. At a Labor Relations Commission hearing, it is not only the reasonableness of the action but also its timing, how the individuals were selected, and consistency with past cases that come up all at once. What this concept really changes is not the substance of personnel decisions but the timing of the decision and its paper trail.

The remedy process runs on a fixed clock. A remedy application must be filed with the Regional Labor Relations Commission within 3 months of the act (or of its end, if it is ongoing). A review by the National Labor Relations Commission must be requested within 10 days of receiving the initial ruling, and an administrative lawsuit within 15 days of service of the review ruling. Unlike remedies for unfair dismissal, the labor union itself can be the applicant, the rules also apply to workplaces with fewer than 5 regular employees, and separate criminal penalties apply. Financial assistance is not banned across the board either. Pay within the time-off limit, a small union office, and donations for welfare funds or disaster relief are permitted exceptions.

The most common blind spot in the field is the assumption that it is just one team leader's personal opinion. Under the Trade Union Act, an employer includes anyone who acts on the business owner's behalf in personnel and labor matters, so a line leader's remark at a company dinner such as "joining a union will hurt your promotion" becomes the company's liability. At the hearing, a single KakaoTalk screenshot or three minutes of a morning-meeting recording becomes the key evidence. Employers are not banned from expressing opinions, but the moment an implied benefit or a hint of disadvantage is mixed in, it crosses into interference. The same applies to offering meeting rooms and bulletin boards to only one union in a multi-union workplace, and a ruling brings the added burden of posting the remedial order notice at the workplace. Each case is judged differently, so we recommend review by a labor relations specialist.

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💡 In plain English
Protesting to a referee is different from trying to bribe one. The latter voids the game itself.
Why it matters in practice
Unfair labor practices usually begin not with a major decision but with a single remark on the shop floor. That is why training is the only real way to prevent them.
Origin and sources

Korea's Trade Union and Labor Relations Adjustment Act prohibits unfair labor practices, defined to include discriminatory treatment, yellow-dog contracts, refusal or neglect of collective bargaining, and interference with or financial support of a union. It also provides a remedy process through the Labor Relations Commission (Article 81, among others).

Source · Trade Union and Labor Relations Adjustment Act, Article 81
An example

Company A, an electronic components maker in the Seoul metropolitan area, has 310 employees and KRW 85 billion (≈ US$63,594,200) in annual revenue. A merger of three production lines, under review since March, called for reassigning 12 employees. Six weeks before the planned orders, the production workers filed to form a union. The HR team was caught between the worry that issuing orders now would look like retaliation and the shop floor's demand that delay would stall the lines. (Hypothetical example)

  1. The HR lead bundled seven documents in chronological order, from the March consolidation proposal to the August selection list, and wrote a one-page account showing the matter had already been decided before the union was formed.
  2. The head of production standardized the morning-briefing message to “Whether to join is each person’s own decision, and the company does not get involved,” and banned outright any conversation in which team leaders ask members whether they have joined.
  3. Together with a labor law firm, we ran a 2-hour session for 28 line and shift leaders, going through five labor commission rulings and breaking down, sentence by sentence, “what you can say and what you can’t.”
  4. Union-related contact was consolidated under a single labor-relations deputy manager, and an internal notice made it a rule that any inquiry a team leader receives must be passed to that manager within 24 hours.
  5. The HR director met each of the 12 employees to be reassigned for 30 minutes, explained the selection criteria and changes in terms, and kept 12 interview records signed by each employee.
  6. Two months after the transfer orders, the union's two unfair labor practice complaints ended with one withdrawn and one dismissed, and the line consolidation finished on schedule with all 12 employees reassigned.
Related terms
Training linked to this term
📚Workplace Harassment Prevention and Abuse-of-Power Prevention TrainingNanum Consulting Corporate Training · On-site/OnlineView course →
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Last updated 13 Sep 2026 · Reviewed by John Kim

FAQ

Asking whether someone has joined a union, voicing support for or criticism of a particular union, and actions that affect union operations can all qualify. Because conduct may be judged regardless of intent, caution is needed.
Disadvantageous treatment because of union activity is prohibited. However, union membership does not shield an employee from legitimate personnel action, and you must be able to document that the reasons and criteria are objective.
Support that could amount to financial assistance is restricted. However, some conveniences are permitted within the limits of the law, so specific items need to be checked against the statute and with an expert.
If a remedy application is filed with the Labor Relations Commission, it goes through investigation and a hearing, and a remedial order may be issued. Appeals lead to review and litigation. Separate criminal penalties also exist.