Documenting Multisig Custody for Estate Planning
How family offices can prepare multisig documentation that trustees and estate counsel can act upon.
Multisig arrangements distribute signing authority across family members, advisors, and sometimes institutional cosigners. They reduce single-point-of-failure risk but complicate succession planning: a trustee who inherits authority over traditional assets may have no map to the family’s 2-of-3 Bitcoin custody.
Estate counsel routinely asks three questions about digital asset custody: who can sign, what happens when a signer dies or becomes incapacitated, and whether recovery can proceed without violating the multisig quorum. A multisig documentation appendix answers these in plain language.
Elements trustees need
Signer roster with succession substitutes. Each cosigner position should name a primary holder, their contact protocol, and a designated substitute who can assume the role upon defined triggering events.
Quorum explanation. Trustees who have never used a hardware wallet need to understand that a 2-of-3 arrangement requires two cooperating signers—not one person with a password.
Recovery scenarios. Document at least three scenarios: normal operation, one signer unavailable, and catastrophic loss of multiple signers. Each scenario should describe which parties act, in what sequence, and what physical items they need.
Geographic considerations. When signers reside in different jurisdictions, note time-zone constraints, travel requirements for in-person signing, and any legal restrictions on key transport.
Coordination with estate counsel
We recommend a joint review session between register specialists and estate counsel before finalising the appendix. Counsel may request language adjustments to align with trust instrument definitions. Allow two weeks for this review in your project timeline.
Limits of documentation
Documentation describes custody; it does not replace legal instruments. Trust language, letters of wishes, and corporate resolutions should reference the appendix by name and date. The register and appendix together form the operational layer beneath legal authority.