CUSTODY

Best Bitcoin Collaborative Custody Services

Unchained

Unchained pioneered the collaborative custody model in Bitcoin. Their standard product is a 2-of-3 multisig vault: the client holds two keys on separate hardware wallets, Unchained holds the third as a recovery key. Unchained cannot move Bitcoin unilaterally, but can cosign if the client loses a key. This structure means the client retains sovereign control while eliminating single-point-of-failure risk.

Beyond custody, Unchained has built a full Bitcoin financial services stack: a Bitcoin IRA with collaborative custody, a trading desk that settles directly into client vaults (no exchange counterparty risk), business lending, and estate planning services. For Bitcoin-only holders who want an integrated approach, this is the most complete platform in the category.

Pricing is straightforward. The free tier includes a standard vault with pay-per-cosign ($20 per signature when Unchained’s key is needed). Most clients only need Unchained’s key during key loss or when they’re traveling — so the free tier works for many holders. The $250/year premium vault removes the per-cosign charge and adds priority support and some inheritance features.

Unchained requires KYC at onboarding. This is a tradeoff for U.S. regulatory compliance and for access to services like the IRA and lending. Hardware wallet support is restricted to Ledger, Trezor, and Coldcard — less permissive than competitors but covers the most common options.

AnchorWatch

AnchorWatch is the only collaborative custody service that includes real insurance. As a Lloyd’s of London Coverholder, AnchorWatch writes policies on A+-rated paper, with binding authority up to $100 million per customer. The insurance covers permanent loss of control of Bitcoin in an insured vault, including physical perils (fires, floods, tornadoes), theft, coercion, and certain disaster scenarios. Payouts are denominated in USD based on Bitcoin’s value at claim time.

The technical model is different from traditional 2-of-3 collaborative custody. AnchorWatch’s Trident Vault uses Bitcoin’s native smart contracting language (miniscript) to build what the company calls a “multisig of multisigs.” The customer holds their own 2-of-3 key set, and AnchorWatch holds its own separate multisig key set. Both must independently complete signatures before a transaction can broadcast. AnchorWatch cannot move Bitcoin unilaterally. After the insurance policy ends, time-locked recovery paths allow the vault to become pure self-custody — the customer doesn’t need AnchorWatch to remain operational long-term.

Pricing has two components. Insurance premiums start at 0.55% of vault value annually. A Technology Service Fee (TSF) of up to 0.25% covers the custody software and support; TSF is waived on the first $250,000 in the vault. A one-time onboarding fee applies, refundable if coverage is denied. Policies are 12 months and renewable.

AnchorWatch is currently available only to U.S. customers, though American LLCs that wholly own Bitcoin can access the service globally. The $250,000 minimum vault size and institutional focus make this a product specifically for meaningful holdings. It is not a first-vault option for small holders.

Casa

Casa built its reputation on making multisig accessible. The Standard plan ($250/year) is a 2-of-3 vault where the client holds two keys across separate hardware wallets and Casa holds a recovery key. Casa cannot spend funds unilaterally — their key exists as a recovery mechanism only. The Premium plan ($2,100/year) upgrades to a 3-of-5 vault with five keys distributed across the client’s devices and Casa’s backup, plus video-verified support and family co-management for inheritance.

What differentiates Casa is the product experience. The mobile app is mature, the health-check features prompt users to verify keys periodically, and the onboarding handles much of the complexity that trips up DIY multisig users. For holders whose primary concern is operational usability — not wanting to manage complex setups manually — Casa is the strongest option.

Casa includes inheritance planning (Casa Covenant) across all paid tiers. This is a meaningful difference from Unchained, where inheritance is a separate service. Casa Covenant lets the client designate beneficiaries and structures key inheritance so heirs can access Bitcoin without needing multisig technical knowledge themselves.

Two considerations. Casa supports Bitcoin, Ethereum, USDC, and USDT — the multi-asset support is a feature for some users but dilutes the Bitcoin-only focus that matters to others. Casa does not require KYC at entry, though it offers video verification as an option. Hardware wallet compatibility covers the main options: Ledger, Trezor, Coldcard, Foundation Passport, and Keystone.

Nunchuk

Nunchuk is both the most permissive and the most philosophically distinct option in the category. The free tier is a fully DIY multisig wallet — no collaborative custody relationship, no platform key, just open-source multisig software with the broadest hardware wallet support available. Paid tiers add collaborative custody through Nunchuk’s platform key.

The Iron Hand plan ($120/year) is a 2-of-3 assisted multisig: the client holds all keys, and Nunchuk’s platform key automates co-signing based on user-defined policies. The Honey Badger plan ($480/year) is a 2-of-4 assisted multisig with inheritance planning included. In both cases, Nunchuk holds a platform key that serves functional co-signing roles rather than human-operated recovery — a distinctly different approach from Unchained’s or Casa’s concierge-style service model.

Nunchuk’s commitment to privacy is genuine and documented. The company requires no personal information beyond an email address. There is no KYC at any tier. Nunchuk’s open-source wallet has been independently adopted by high-profile cases including the 2022 Canadian Freedom Convoy fundraiser, where the multisig architecture protected funds even under legal pressure. For holders whose threat model includes government overreach, this matters.

The tradeoff is less hand-holding. Nunchuk is closer to sophisticated software with a support tier than to a white-glove custody service. Technical setup expectations are higher than with Casa. The inheritance solution in Honey Badger is newer than Casa Covenant or Unchained’s estate planning, though it uses on-chain timelocks designed to function even if Nunchuk as a company disappears.