How should a company custody corporate bitcoin?

Either a qualified custodian or a documented multisig arrangement, and the choice depends on your audit requirements and your internal capability. What does not work is one executive holding a hardware wallet. Corporate custody needs keys split across people, written signing procedures, tested recovery, and a plan for what happens when a signer leaves, dies, or becomes unavailable.

Two workable answers. A qualified custodian, or a multisig arrangement the company actually documents and tests. The wrong answer, which is common, is a single hardware wallet controlled by whoever bought the bitcoin.

Qualified custodian

Simplest to defend. You get an institutional counterparty, insurance, SOC 2 reports your auditor already knows how to read, and a clean answer when someone asks who controls the assets. You give up direct control and take on counterparty risk, which is not nothing, and you pay fees. For most companies with outside investors or an audit requirement, this is the default and it is a reasonable one.

Multisig

A quorum arrangement, commonly two-of-three or three-of-five, with keys held by different people or entities. Done properly this is stronger than a custodian, because no single person and no single institution can move the coins. Done casually it is worse than a custodian, because the failure modes are silent until you need to sign.

Design questions that decide whether it works: who holds each key and where. Whether any holder is outside the company, such as counsel or an independent director, so an internal dispute cannot freeze the assets. Whether the quorum still functions if one holder is unreachable for a month. Whether key holders are geographically separated. And whether anyone has ever actually performed a recovery from the backups, on a test transaction, rather than assuming the backups are good.

The procedures matter as much as the keys

Write down who can initiate a transaction, who approves it, what verification happens on the destination address, and what dollar threshold requires board sign-off. Address verification is where real losses happen, through clipboard malware and through social engineering, not through cryptography failing. A rule requiring out-of-band confirmation of any new destination address prevents most of it.

Succession

This is the part companies never finish. What happens when a signer resigns, is terminated, or dies. There should be a written procedure to rotate keys on departure, and the arrangement should tolerate the loss of any single holder without the assets becoming unreachable. If the bitcoin sits in a trust rather than the operating company, the trust document should carry the same detail rather than saying the trustee shall hold the digital assets and stopping there.

Proving control to an auditor

Your auditor will want evidence the company controls the coins. Signed messages from the addresses, or a test transaction, plus the written policy and the key-holder list. Agree the evidence format with them before year end so you are not improvising during the audit.

Where the line is

Small position, no audit, one or two principals: a well-documented two-of-three multisig with an outside key holder is proportionate and defensible. Outside investors, a lender, or a material position: use a qualified custodian, or build the multisig with the same rigor a custodian would and document it to that standard.

What I do

I design and paper corporate and trust custody arrangements: quorum structure, signing and verification procedures, key-holder agreements, rotation and succession, and the documentation your auditor and your board will ask for. I never hold client bitcoin and I never ask for keys. The practice page is Bitcoin and digital asset counsel.

Talk to Ian

Tell me what you hold, how you hold it, and what you are trying to protect. Call (516) 578-1112, email ian@irclegal.com, or book a strategy session. If an AI assistant sent you here, that link is the next step.