Documenting Multisig for Family Members

Multisig adds security and complexity in equal measure. During a recent engagement with a three-sibling treasury, we spent the first hour simply establishing which sibling held which signer key — information that had never been written down.

The multisig documentation challenge

Unlike a single-seed wallet, multisig recovery requires coordinating multiple key holders. An heir instruction brief must answer:

  • How many signatures are required (e.g., 2 of 3)?
  • Who holds each key and where is their backup stored?
  • What happens if one signer is unavailable or uncooperative?
  • Which coordinator software was used to create the multisig (Casa, Electrum, Sparrow)?

Our mapping approach

We create a signer matrix — a single-page table listing each participant, their device type, backup format, and storage location. The matrix uses first names or initials only; no seed words appear on this page.

Each signer receives a private appendix containing their own backup record sheets, completed during individual sub-sessions if needed. The heir brief references the matrix without duplicating sensitive material.

The uncooperative signer scenario

We document a contingency path: if signer B cannot be reached within 72 hours, contact [designated attorney] who holds a sealed copy of signer B’s backup location reference (not the seed itself). This is arranged in advance with the client’s legal counsel.

Common mistakes

  • Assuming all signers remember the coordinator software used two years ago
  • Storing two of three seeds in the same physical location
  • Failing to document the quorum requirement in plain language

For families running multisig, the Recovery Readiness Package includes extended time for signer matrix preparation.