Official registered business
File Brook Line Co., Ltd. is registered in the Republic of Korea and operates from Office 6, 64 Sample-gil, Mapo-gu, Seoul 00000.
The company was established in 2019 after our founder spent two years helping expatriate families in Seoul document hardware wallet access following a colleague’s sudden hospitalisation. What began as informal favour-work became a dedicated practice when three families in the same apartment building requested identical quarterly check schedules.
What we do
We schedule, witness, and document periodic offline wallet access checks. Our technicians work with Ledger, Trezor, Coldcard, and paper-wallet arrangements. We do not hold client funds, manage exchanges, or provide investment guidance.
Our people
The practice employs four custody technicians and one documentation editor. Lead technician Jun-ho Park previously maintained archival records for a Mapo law firm and holds a certificate in information security fundamentals from Korea University Continuing Education. Documentation editor Sarah Whitfield translates custody binders for English-speaking households and coordinates with Korean counsel on inheritance appendices.
Working approach
Every client receives a physical custody binder on first engagement. Quarterly verifications update the same binder rather than generating disconnected PDFs. We believe paper trails survive power outages, account lockouts, and the passage of years better than cloud folders alone.
Values
- Witnessed over assumed: Access is confirmed in person, with signatures.
- Documentation over memory: If it is not in the binder, it did not happen.
- Discretion over display: We do not publish client holdings or portfolio sizes.
Relationship to clients
Most clients remain on a quarterly retainer for three or more years. We serve households across Seoul, with on-site visits available in Gangnam, Seocho, Yongsan, and Mapo without travel surcharge.