Unchained multisig takes a different approach than most custody services: you hold the majority of keys, and Unchained acts as a collaborative partner rather than a custodian. In their 2-of-3 multisignature model, you control two keys on separate hardware wallets while Unchained holds one backup key. This means you can always spend your bitcoin without Unchained’s permission — they’re there to help with recovery and to offer financial services on top of sovereign custody, not to control your funds.
This article explains how Unchained’s collaborative custody model works, what financial services they build on it, and how it compares to both DIY multisig and fully managed solutions.
Multisig in Practice from the
Advanced Bitcoin Security & Privacy course.
How Collaborative Custody Works
Unchained’s vault structure uses standard 2-of-3 Bitcoin multisig. The three keys are distributed as follows:
- Key 1 — Your primary hardware wallet: A hardware wallet you control completely, stored wherever you choose. This is your everyday signing key.
- Key 2 — Your backup hardware wallet: A second hardware wallet stored in a separate physical location — a safe deposit box, a trusted family member’s home, or another secure location. This geographic separation protects against theft, fire, or natural disaster at any single location.
- Key 3 — Unchained’s backup key: Held on Unchained’s enterprise-grade infrastructure, stored in cold storage on air-gapped hardware. This key is only used if you lose one of your keys and need recovery assistance, or when you initiate transactions through Unchained’s web interface for convenience.
The critical distinction: because you hold 2-of-3 keys, you maintain full sovereignty over your bitcoin at all times. You can create and sign a transaction using your two hardware wallets without Unchained’s involvement, permission, or even knowledge. Unchained never has the power to move, freeze, or seize your funds — they hold only one key in a three-key quorum.
This is fundamentally different from traditional custodians (who hold all keys) and from Casa’s model (where you hold 1–2 keys depending on the plan). With Unchained, if the company disappears tomorrow, your bitcoin is unaffected — you sign with your two keys using any standard multisig-compatible wallet.
Financial Services Built on Multisig
What makes Unchained unique isn’t just the custody model — it’s the financial services layered on top of collaborative custody.
Bitcoin IRAs
Unchained offers Individual Retirement Accounts (IRAs) where your bitcoin is held in a multisig vault — not by a third-party custodian. You still control two keys while Unchained acts as the IRA custodian for regulatory compliance. This provides tax-advantaged bitcoin savings (Traditional or Roth IRA) with genuine self-custody rather than the custodial model most Bitcoin IRA providers use.
IRA pricing includes a $995 setup fee (covers the first year), $250/year after that, and a 0.50% fee on bitcoin purchases and sales within the IRA.
Bitcoin-Backed Loans
Borrow USD against your bitcoin without selling. Your collateral stays in multisig — Unchained can co-sign loan-related transactions using their key, but you still hold two keys and can verify the collateral at any time on-chain. This is useful for accessing liquidity without triggering a taxable event from selling bitcoin.
Inheritance Protocol
Unchained’s inheritance feature lets you designate beneficiaries who can work with Unchained to access your bitcoin after your death. The process combines legal documentation (a will or trust) with key access — your beneficiary provides legal proof of inheritance and works with Unchained’s key to reach the 2-of-3 threshold. For alternative inheritance approaches, see our multisig inheritance planning guide.
Business Treasury
Companies can hold bitcoin treasury in collaborative custody with multi-user signing authority. Multiple authorized signers within the organization each hold a hardware wallet key, with Unchained providing the backup key and the platform for transaction coordination.
Vault Setup Process
- Create an Unchained account — KYC is required for all services. Provide identity verification and set up your account.
- Prepare two hardware wallets — Unchained supports Trezor, Ledger, and Coldcard. Each wallet generates a key that participates in the multisig.
- Configure the vault — Through Unchained’s web interface, connect both hardware wallets and let Unchained generate their backup key. The platform creates the 2-of-3 multisig configuration and provides you with the wallet descriptor for your records.
- Verify and fund — Verify the receiving addresses on both hardware wallet screens (critical security step), then send a small test deposit. Once confirmed, fund your vault with your desired amount.
- Store hardware wallets securely — Place your two hardware wallets in separate secure locations along with their seed phrase backups.
Pricing
| Service | Cost |
|---|---|
| Personal Vault | No annual fee |
| Business Vault | $250–$2,500/year |
| IRA Setup | $995 (includes first year) |
| IRA Annual Fee | $250/year |
| IRA Trading Fee | 0.50% per transaction |
| Bitcoin-Backed Loans | Variable interest rates |
The personal vault being free is significant — you get professional-grade multisig infrastructure with a collaborative backup key at no ongoing cost. Revenue comes from the financial services built on top.
Pros and Cons
Pros
- True self-sovereignty: you hold 2-of-3 keys and can spend without Unchained’s involvement
- No company risk: if Unchained disappears, your bitcoin is fully accessible with your two keys
- Free personal vaults — no subscription required for basic multisig custody
- Financial services (IRAs, loans, inheritance) built natively on multisig security
- Business treasury support with multi-user signing
- Standard multisig format — compatible with any wallet that supports P2WSH
- Strong educational content and onboarding support
Cons
- KYC required for all services — not suitable for privacy-focused users
- Unchained can see your vault activity (they hold an xpub)
- Financial services are US-focused — international availability is limited
- Web-based interface for vault management (no dedicated mobile app)
- IRA fees are higher than some traditional custodial Bitcoin IRA providers
- You must manage two hardware wallets and their seed phrase backups
Unchained vs Casa vs DIY
| Factor | Unchained | Casa | DIY (Sparrow) |
|---|---|---|---|
| Sovereignty | Full (2 of 3 keys) | Partial (1–2 of 3/5) | Full (all keys) |
| Company risk | None | Moderate (recovery tool mitigates) | None |
| Financial services | IRAs, loans, inheritance, treasury | Inheritance only | None |
| Technical skill needed | Medium | Low | High |
| KYC | Required | Required (higher tiers) | None |
| Mobile app | No (web interface) | Yes | No (desktop) |
| Cost | Free (personal vault) | $250+/year | Free |
Unchained is the best option if you want true sovereignty combined with institutional-grade financial services. Casa is better if simplicity is your priority and you’re willing to trade some sovereignty for convenience. DIY with Sparrow is for users who want zero third-party involvement and have the technical skill to manage it. For a complete analysis of all options, see our lesson on Multisig in Practice.
Who Should Use Unchained?
Unchained is the right choice for:
- Bitcoin holders who want multisig security without giving up key majority — true self-custody with a professional safety net
- Anyone wanting a Bitcoin IRA with genuine multisig custody rather than trusting a custodian
- Users who may need bitcoin-backed loans without selling their stack
- Businesses holding bitcoin treasury who need multi-user signing authority
- Families planning bitcoin inheritance with professional protocol support
Verdict
Unchained occupies a unique position: the only major platform that gives you genuine key majority (2-of-3) while building a full suite of financial services on top. You get the security benefits of collaborative multisig without sacrificing the sovereignty that makes self-custody meaningful. The free personal vault makes this accessible to anyone willing to manage two hardware wallets.
The KYC requirement means Unchained isn’t for privacy-maximizers. But for bitcoiners who need IRAs, loans, inheritance planning, or business custody — all built on a model where you genuinely control your own keys — Unchained delivers something no other platform currently matches.
Frequently Asked Questions
Can I access my bitcoin if Unchained goes offline?
Yes. You hold 2-of-3 keys on hardware wallets you control. You can sign transactions using any multisig-compatible wallet software (Sparrow, Electrum, Nunchuk) without Unchained’s involvement. This is the fundamental advantage of collaborative custody over traditional custodial models.
Do I need two different hardware wallet brands?
Not required, but recommended. Using two different manufacturers (e.g., one Trezor and one Coldcard) protects against a firmware vulnerability in any single brand. Two devices from the same manufacturer still provide strong multisig security — the keys are independent regardless.
How does the Bitcoin IRA work from a tax perspective?
Unchained offers both Traditional and Roth IRAs. Traditional IRA contributions may be tax-deductible, with taxes paid on withdrawal. Roth IRA contributions are made with after-tax dollars, but qualified withdrawals are tax-free. Consult a tax professional for your specific situation — Unchained provides the custody infrastructure, not tax advice.
Is Unchained available outside the US?
The vault feature is available internationally, but financial services (IRAs, loans) are currently US-only due to regulatory requirements. International users can still use Unchained’s collaborative custody for secure bitcoin storage.
