Part of the CustodyStress archive of observed Bitcoin custody incidents
Multisig quorum failure
Cases in this category involve multisig arrangements where the required number of signers was not available to authorize a transaction.
Multisig quorum failures arise when the signing threshold cannot be reached due to key holder unavailability, not due to key loss. Cases span personal inheritance setups, corporate treasury arrangements, and protocol-level governance structures. The common pattern is a quorum requirement designed for security that becomes a coordination barrier when key holders are unavailable, unresponsive, or in dispute.
77 observed cases
Blocked
5 (6%)
Constrained
7 (9%)
Survives
56 (73%)
Indeterminate
9 (12%)
Multisig quorum failure — hardware wallet — United States 2025
Hardware wallet (single key)
A 2025 estate case involved a 2-of-3 multisig wallet where the deceased holder had kept one key, a professional fiduciary firm held the second, and a hardware k
The holder wanted to migrate the funds to a new wallet but required 2-of-3 signatures
Hardware wallet (single key)
A 2025 case involved a 2-of-3 multisig arrangement where one of the three hardware keys had been manufactured by a company that went out of business in 2024. Th
Hidden wallet discovered — institutional custody (2025)
Institutional custody
A 2025 Bitcoin custody service consolidation saw two mid-sized collaborative custody providers merge. During the merger integration period, customers of the acq
The third device had been destroyed in a vehicle fire months before the holder's death.
Hardware wallet (single key)
A 2025 estate case involved a 2-of-3 multisig where the deceased had held all three keys personally—a configuration that negated the quorum safety benefits beca
Multisig quorum failure — hardware wallet (2025)
Hardware wallet (single key)
A 2025 multisig recovery case involved a 3-of-5 wallet where two of the five key holders had each independently lost their signing devices without retaining the
Multisig quorum failure — institutional custody (2025)
Institutional custody
A 2025 case involved a Unchained Capital vault customer whose co-signing arrangement required periodic identity re-verification. After an extended period of non
After the holder failed to respond to multiple re-verification requests over a 12-month
Hardware wallet (single key)
A 2024 Unchained Capital collaborative custody case involved a 2-of-3 multisig arrangement where one of the three keys was held by Unchained as a backup key. Th
The remaining two key holders could technically reach quorum to spend Bitcoin.
Hardware wallet (single key)
A 2024 case involved a 2-of-3 multisignature wallet where one of the three key holders had died unexpectedly. The remaining two key holders could technically re
The professional service had been wound down in 2023 and was no longer operating.
Hardware wallet (single key)
A 2024 estate case involved a 3-of-5 multisignature wallet where the deceased holder had held two of the five keys, a trusted friend held one, and two further k
Multisig quorum failure — hardware wallet (2024)
Hardware wallet (single key)
A 2024 Casa multisignature custody case involved a 2-of-3 setup where the holder's mobile key was stored on a phone that had been factory-reset after the holder
Multisig quorum failure — 3-of-5 multisig (2024)
Institutional custody
A 2024 institutional Bitcoin custody case involved a family office that had established a 3-of-5 multisignature arrangement using a custody service. One of the
Multisig quorum failure — institutional custody (2024)
Institutional custody
A 2024 exchange infrastructure case involved a Bitcoin lending platform that used multisignature cold storage for customer funds with signing keys distributed a
Customer withdrawals were suspended for 36 hours while the hardware failure was
Institutional custody
A crypto custody provider that used a distributed key management system experienced a quorum failure in September 2023 when a key server in one of three geograp
Multisig quorum failure — 3-of-5 multisig (2023)
Hardware wallet (single key)
A family holding entity using a 3-of-5 multisignature wallet encountered quorum failure when two key holders died within six months of each other in 2023. The d
Multisig quorum failure — 2-of-3 multisig (2023)
Institutional custody
A corporate treasury that had held Bitcoin in a 2-of-3 multisignature arrangement since 2021 encountered quorum failure in 2023 when one key holder—a board memb
Sanctions lockout — 3-of-5 multisig (2023)
Institutional custody
A US-based investment fund that had established a 3-of-5 multisignature Bitcoin custody arrangement in 2021 encountered signing complications in 2023 when two k
The attorney died unexpectedly, leaving the family with access to only two of three
Institutional custody
A family-run Bitcoin holding entity had established a 2-of-3 multisignature wallet with keys held by two brothers and a family attorney. In April 2022, the atto
Platform bankruptcy — FTX (2022)
Institutional custody
Multiple institutional custody arrangements that had relied on FTX as a co-signer or custodian in multisignature wallet configurations lost access to funds when
Multisig quorum failure — 2-of-3 multisig (2022)
Institutional custody
A crypto investment fund using a 2-of-3 multisignature custody arrangement lost effective access to its Bitcoin holdings in June 2022 when one key holder—a co-f
Multisig quorum failure — software wallet 2021
Mobile or software wallet
A Bitcoin inheritance structure using a 3-of-5 multisig faced an unintended lockout in November 2021. The grantor updated the trust structure but the legal upda
One key holder relocated to a country under US sanctions in October 2021.
Mobile or software wallet
An October 2021 case describes a family Bitcoin trust using a 2-of-3 multisig. One key holder relocated to a country under US sanctions in October 2021. The rem
Multisig quorum failure — 4-of-7 multisig (2021)
Mobile or software wallet
A DeFi protocol's 4-of-7 multisig treasury was paralysed in May 2021 when two key holders — both anonymous pseudonymous developers — disappeared after a governa
A cryptocurrency fund's 3-of-5 multisig was compromised in June 2021.
Exchange custody
A cryptocurrency fund's 3-of-5 multisig was compromised in June 2021. One key holder's credentials were phished. The attacker gained control of one key and then
Multisig quorum failure — exchange custody (2021)
Exchange custody
A DAO treasury held in a 2-of-3 Gnosis Safe multisig was compromised in July 2021 when one key holder's private key was phished through a malicious governance p
One key holder was hospitalised and a second was unreachable following a personal
Mobile or software wallet
A Bitcoin startup used a 2-of-3 multisig. In February 2021, one key holder was hospitalised and a second was unreachable following a personal emergency. The thi
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