Can I file a dismissal invalidity lawsuit if I was unfairly dismissed?

A dismissal invalidity lawsuit is a lawsuit to deny the effect of a unilateral dismissal disposition by the employer and to have its invalidity confirmed by the court.

That is, it is a procedure in the form of civil litigation filed by a worker to claim reinstatement to the original position and payment of wages equivalent to the dismissal period when the employer's dismissal was unfair or made without just cause.

First, the unfair dismissal remedy application and the dismissal invalidity lawsuit are different systems.

The unfair dismissal remedy application is a procedure for applying for remedy to the labor commission under Article 28 of the「Labor Standards Act」, which must be filed within 3 months from the date of dismissal.

In contrast, a dismissal invalidity lawsuit is a rights remedy procedure under civil law, with no special filing period restrictions (however, restrictions may apply if violating the principle of good faith), and can be conducted in parallel with the labor commission remedy application or separately.

Additionally, the burden of proof lies with the employer.

That is, the employer must prove to the court that the dismissal was justified (managerial reasons, neglect of duty, disciplinary reasons, etc.), and the worker has no obligation to prove this.

If the court judges that there is no just cause for dismissal, the dismissal becomes invalid and the effect is deemed to have not existed from the beginning.

However, please note that if you have received severance pay or engaged in a new occupation for a long time after dismissal without raising any objections, the court may consider this as recognizing the effect of the dismissal and dismiss the lawsuit according to the principle of good faith (principle of forfeiture).

Therefore, if you have been unfairly dismissed, it is desirable to consult with a legal expert without delay and conduct appropriate remedy procedures in parallel.