Guides / Glossary / Collaborative multisig
Glossary

Collaborative multisig: shared keys with a provider

A multisig arrangement in which the company holds most of the keys and a specialist provider holds one, so the provider can help but never move funds alone.

Education only

Definition. A 2 of 3 multisig where the company holds two keys and a specialist provider holds the third. The provider cannot move funds alone.

How it works

In a typical collaborative set up, the company holds two of three keys on its own hardware signing devices and a provider holds the third. Day to day, the company can sign with its own two keys and needs nothing from the provider. If one company key is lost, the provider's key plus the remaining company key can still sign, usually after identity checks and a waiting period set out in the provider's terms. The provider alone holds only one key, so it cannot spend.

Some services also offer software, inheritance planning, key replacement and support. Those extras vary, and the legal terms matter as much as the technology: what checks the provider runs before co-signing, how long it takes, what happens if the provider closes, and whether the company can recover without it.

Why it matters for a company

Collaborative multisig sits between doing everything yourself and handing the bitcoin to a custodian. The company keeps control, which avoids the risk of a custodian failing or freezing withdrawals, while a professional third key reduces the chance that a lost device becomes a lost treasury. For a small company without an in-house security team, that balance is often the attraction.

The independence of the company's own recovery path is the key test. If the provider disappears, the company should still be able to rebuild the wallet from its two keys and the wallet descriptor, using open source software. Ask the provider to show how, and test it.

Example only, fictional. A small engineering firm keeps one key with its finance director, one in a bank safe deposit box and one with a collaborative custody provider. When the finance director's device fails, the firm signs a sweep to a new wallet using the safe deposit key and the provider's key, then retires the old wallet.

Common mistakes

Sources

Primary sources only. Each link was checked on 9 November 2026. Rules change, so confirm the current version with your adviser.

  1. Bitcoin BIPsBIP 11: M of N standard transactions (multisig)
  2. NISTSP 800-57 Part 1 Rev. 5: Recommendation for key management
  3. FCACryptoassets: AML and CTF regime (registration, no FSCS or Ombudsman cover)
  4. US CFR17 CFR 275.206(4)-2, custody rule for investment advisers (definition of qualified custodian)
Education, not advice.

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