Japan's Private Investigation Business Act requires agencies to register with the prefectural public safety commission. Registration is a minimum requirement — it does not guarantee quality.
For foreigners, there are extra things to check: language support, willingness to explain the contract, and experience with clients who are not Japanese nationals.
Verify registration
Check the agency’s current detective-business marker (標識) on its website. Since April 2024, the old prefectural notification certificate (探偵業届出証明書) has been abolished. The marker should identify the operator, office, Public Safety Commission, filing date, and notification number; stated website-publication exceptions may apply.
What to confirm before signing
Ask for a written, itemized quote and check:
- Total cost (not just the headline rate)
- Number of investigators included
- Vehicle and transport fees
- Report preparation fee
- Overtime rate and when it applies
- Exact definition of "success" if on a success-fee plan
- Cancellation conditions
- How your data and report will be stored and deleted
The contract is in Japanese — what to do
You have the right to take the contract away before signing. Run it through a translation tool, ask a bilingual friend to check it, or request that the agency summarize key clauses in writing.
At minimum confirm: total price, what triggers additional charges, cancellation terms, and how the report is delivered.
Green flags
Trustworthy agencies tend to:
- Provide a written quote without pressure
- Explain risks and limitations clearly
- Give you time to decide
- Show a sample report (with identifying details removed)
- Decline clearly illegal or discriminatory requests
- Be transparent about how they handle your data
Red flags
Be cautious if an agency:
- Presses you to sign on the first call
- Advertises an extremely low price but is vague about extras
- Cannot define what "success" means in a success-fee plan
- Guarantees a result
- Refuses to provide a written quote or contract
See the How it works page for what happens after you choose an agency, and the Pricing guide for quote details.
FAQ
Does registration mean the agency is reliable?
Registration is a legal minimum but does not guarantee quality or ethics. Check the contract, the quote, and how they answer your questions.
Can I consult multiple agencies before deciding?
Yes — this is standard practice. Getting two or three quotes and comparing both price and communication style is sensible.
Can the quote change after I sign?
It can if there are additional-charge conditions you agreed to (overtime, expanded area, etc.). Make sure all conditions are written in the contract before you sign.