Documenting Seed Phrase Custody Chains Without Creating New Risk

Continuity notes must describe custody without reproducing secrets. Here is how we structure seed phrase documentation for founder teams.

Founders frequently ask whether continuity documentation should include seed phrases, partial phrases, or checksum words. Our answer is always no. A continuity document that contains secrets becomes the weakest link in your custody chain — copied to shared drives, emailed during reviews, or left on printers.

The goal is to document who holds what and how they coordinate, not to duplicate the secrets themselves.

The custody chain model

We document seed phrase custody using a chain model:

Holder → Fragment type → Storage location → Access conditions → Contact method

An example entry (with fictional names):

Holder: Soo-jin Lee (CFO)
Fragment type: Words 1–8 of primary wallet seed
Storage: Safe deposit box, Cheongju branch, Box 447
Access conditions: Requires Lee’s key + company authorization letter
Contact: lee@company.com, +82-10-XXXX, available Mon–Fri 09:00–18:00 KST

This tells an emergency responder where to start without revealing any seed content.

What we never include

  • Full or partial seed phrases
  • Private keys or derivation paths
  • Wallet balances or transaction histories
  • Photographs of seed phrase cards

Fragment distribution patterns we commonly document

Single holder, single location. One founder holds the complete seed in a home safe. Simple but creates succession risk if that founder is unavailable.

Split across co-founders. Words divided between two or three people, each stored separately. Requires coordination documentation describing the assembly process without listing the words.

Geographic distribution. Fragments held in different countries for jurisdictional or travel-risk reasons. Requires timezone and communication protocol notes.

Corporate vault with personal backup. Primary in company safe, backup fragment with external advisor or family member. Requires clear authority documentation for who can request access.

The assembly procedure

For split custody, the continuity note includes an assembly procedure:

  1. Which holders must be present (minimum set for quorum)
  2. Communication channel for coordination (not email for initial contact — usually a pre-agreed phone tree)
  3. Physical location where assembly occurs
  4. Verification step before any transaction (e.g., test signature on small amount)
  5. Time window expectations (how long assembly typically takes)

Again, no secret content — only process.

Review triggers

Seed phrase custody documentation should be reviewed when:

  • A holder changes role or leaves the company
  • Physical storage location changes
  • The wallet setup changes (new device, different multisig threshold)
  • Annually, as part of a continuity drill

Request a cold storage documentation review to assess your current records.