When Your Employer Prohibits Side Work in Japan
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Last Updated:
Category: Side Jobs
Authors: Shusaku Yosa
If your employer says side work is prohibited, read the actual policy and ask how it operates. A blanket restriction, a permission system and a rule covering only certain activities lead to different next steps. This guide concerns private-sector employment; public-service and profession-specific restrictions need separate review.
Describe the activity rather than relying on its name
Activity | Questions |
|---|---|
Second employee job | Hours, concurrent employment and permission requirements |
Contracting or a business | Counterparty, duties, competition and information handling |
Selling creative work or monetized content | Scale, continuity and policy coverage |
Selling belongings | Occasional disposal or repeated buying for resale? |
Investing | Employer dealing rules and professional restrictions; investment losses are a separate risk |
A small amount of income, an online activity or the absence of an employment contract does not automatically place an activity outside the policy. Investing is not a guaranteed substitute income. Compare the facts with the wording and seek clarification where needed.
Identify the employer’s concern
MHLW guidance discusses effects on the main job, confidential information, competitive harm and trust or reputation. Ask which concern applies to your proposal. Do not assume that disagreement with a general explanation makes it safe to ignore the procedure. A labor consultation service can help if the policy or a specific measure is disputed.
Propose practical conditions
- Limit the activity and check customer or competitor overlap.
- Set days and an hours ceiling, with adjustments during busy periods.
- Keep employer equipment, customer lists and unpublished material separate.
- Agree on a trial period and a date to review workload.
- Report material changes or the end of the activity.
An inquiry might say: “I am considering [activity]. Could you clarify whether it is covered and under what conditions approval may be possible? I propose [schedule] and will not use company materials or customer information.” Keep the response and resolve approval before accepting or starting work where approval is required.
Prepare without taking paid assignments
You can consider learning from public materials, creating an original practice portfolio, mapping available time and comparing job descriptions. Check any broader external-activity rules and never use confidential employer material. Before paying for an expensive course, identify the skills you actually need and the time available to use them.
Compare longer-term options
Clarify whether the purpose is additional income, skill development or changing occupations. Internal transfers, changed responsibilities, another policy discussion or a job search may also serve that purpose. Review living costs and income continuity before deciding to resign. A different tax collection method does not override employment rules.
Related guides
Sources and official guidance
Information checked September 25, 2026. This guide concerns Japan. Consult the relevant authority or current listing for your circumstances; linked Japanese guidance is authoritative.
