Bitcoin Collaborative Custody Comparison: Casa vs Unchained vs Nunchuk

Collaborative Custody Services Compared

Collaborative custody sits between full self-custody and third-party custodians. The model uses multisig wallets where the user holds the majority of keys and a service provider holds one key as a recovery backstop. The provider can never move funds unilaterally, but can co-sign transactions when the user loses a key or needs assisted recovery.

Three commercial providers dominate this space: Casa, Unchained, and Nunchuk. Each offers guided key management, inheritance planning, and hardware wallet integration, but they differ in pricing, key architecture, and additional financial services. For users who want full control without a service provider, open-source tools like Sparrow Wallet and Caravan enable DIY multisig setups.

For a broader look at multisig configuration options beyond these providers, see the Bitcoin multisig setup comparison.

Casa: Mobile-First Security

Casa focuses on making multisig accessible through a polished mobile app. The Standard tier ($250/year) provides a 2-of-3 vault where the user holds two keys (one on a mobile device, one on a hardware wallet) and Casa holds one recovery key. The Premium tier ($2,100/year) upgrades to a 3-of-5 vault distributed across four user-controlled keys and one Casa recovery key, and includes three hardware devices, Faraday bags, and tamper-evident packaging.

Casa's anti-social-engineering features set it apart. Guardian Mode (Premium and above) requires live video verification with two Casa advisors plus a 48-hour hold before Casa will co-sign. Address whitelisting enforces a 48-hour waiting period for new addresses. The app detects active phone calls during send attempts, since roughly 20% of social engineering attacks begin with an unexpected phone call. Emergency lockdown freezes all vault activity for 72 hours on Standard or until video-verified on Premium.

Beyond Bitcoin, Casa expanded in 2025 to support ETH, USDT, and USDC in multisig vaults. Inheritance is available on all paid tiers without requiring KYC: the holder designates a recipient by email, and if a vault access request goes uncontested for six months, the recipient gains access. Private Client tiers include attorney consultations for estate planning. Casa also publishes Sovereign Recovery Instructions, documenting how to recover funds using open-source software without Casa's involvement.

Unchained: Bitcoin Financial Services Platform

Unchained positions itself as a full financial services platform built around collaborative custody. The base vault costs $250/year and uses a 2-of-3 multisig where the client holds two keys on cold storage devices and Unchained holds one. Unlike Casa, which offers 3-of-5 vaults, Unchained standardizes on 2-of-3 across all tiers. The Personal Signature plan ($6,000 first year, $4,500/year thereafter) adds concierge onboarding, a dedicated account manager, up to ten vaults, emergency support, and two hardware wallets.

Unchained's differentiator is its financial services stack. Bitcoin-collateralized loans let clients access dollar liquidity without selling, with over $1 billion in loan volume originated to date. The Bitcoin IRA ($995 setup, $250/year ongoing) supports Traditional, Roth, and SEP structures, and is the only IRA product where the client holds their own keys rather than delegating custody to a third-party trustee. A trading desk enables direct vault purchases at tiered rates: 1.0% under $100K, 0.75% for $100K to $1M, and 0.50% above $1M.

For inheritance, the Unchained Inheritance Protocol provides a document package including key succession checklists, executor letters, and seed phrase cards. A concierge recovery service guides non-technical heirs through the process upon verified death. Transfer-on-death beneficiary designations allow vaults to bypass state probate. Unchained merged with Gannett Trust in October 2025 to expand its wealth management capabilities.

Nunchuk: Programmable Multisig

Nunchuk takes a different approach by offering both free DIY multisig and paid assisted custody, with a strong emphasis on programmability through native Miniscript support. The free tier provides fully self-managed single-sig and multisig wallets. The Iron Hand tier ($120/year) adds 2-of-3 assisted multisig where Nunchuk holds one platform key. Honey Badger ($480/year) uses a 2-of-4 configuration with a dedicated inheritance key, and Honey Badger Premier ($2,100/year) provides 3-of-5 with two inheritance keys.

Nunchuk 2.0, launched in November 2025, introduced autonomous on-chain inheritance using Miniscript and timelocks. After a configurable timelock expires without activity, the platform key is automatically removed from the signing requirement, giving the beneficiary sole control enforced by the Bitcoin network itself rather than by company policy. This is a meaningful technical distinction: inheritance execution does not depend on Nunchuk remaining operational.

Nunchuk supports the broadest range of signing devices: Coldcard, TAPSIGNER, Jade, Ledger, Trezor, SeedSigner, BitBox, Foundation Passport, and Keystone, among others. NFC tap-to-sign with Coldcard and TAPSIGNER simplifies the signing experience on mobile. The Finney tier ($250/year per wallet) targets families and groups with role-based access: majority owner, blind co-signer, and observer roles. In 2026, Nunchuk launched a Taproot multisig wallet beta using MuSig2 for improved privacy and lower on-chain fees. The platform reports securing over $1 billion in Bitcoin through its paid assisted services.

DIY Multisig: Sparrow Wallet and Caravan

For users who want full sovereignty without any service provider involvement, Sparrow Wallet and Caravan provide the tools to set up and manage multisig independently. The tradeoff is clear: maximum control in exchange for full responsibility over key management, backups, and recovery.

Sparrow Wallet is a free, open-source desktop application (Windows, macOS, Linux) built around PSBTs from the ground up. It supports all standard script types including P2WSH for multisig and P2TR for Taproot. Sparrow provides full coin control with Branch and Bound and Knapsack selection algorithms (the same as Bitcoin Core), a byte-level transaction viewer, built-in Tor support, and direct Bitcoin Core node connectivity. Hardware wallet support includes Ledger, Trezor, Coldcard, Keystone, BitBox02, Jade, Passport, and SeedSigner via USB or air-gapped QR and SD card exchange. Version 2.5.2 was released in May 2026.

Caravan is Unchained's free, open-source, browser-based multisig coordination tool. It runs as a stateless web application that stores nothing outside the current browser session: users must safekeep their own xpubs, derivation paths, and redeem scripts. Caravan supports quorums up to 7 keys and P2SH, P2WSH, and P2SH-P2WSH address types. Its primary purpose is as an escape hatch for Unchained clients: even if Unchained ceases operations, any client holding two of three keys can recover funds through Caravan without Unchained's assistance.

Hardware Wallet Compatibility

Hardware wallet support varies across providers. The following table shows compatibility with the most common signing devices used in multisig configurations.

All commercial providers require at least one hardware wallet for multisig vaults. Casa's Premium tier includes three devices in its welcome package. Unchained includes two devices with Signature plans. Nunchuk is bring-your-own-device across all tiers. For detailed guidance on choosing signing devices, see the hardware wallet comparison.

Inheritance and Recovery

Inheritance planning is one of the strongest arguments for collaborative custody over DIY multisig. Without a service provider, heirs must locate multiple seed phrases stored in separate locations, understand how to reconstruct the wallet using the correct output descriptors, and execute the recovery without technical guidance. Collaborative custody providers simplify this with guided recovery processes.

Casa's inheritance requires no KYC: the holder designates a recipient email, and if a vault access request goes unanswered for six months, the recipient gains access through a free Casa account. Unchained's approach is more document-heavy, with a full inheritance protocol package and concierge service that walks heirs through recovery upon presentation of a death certificate. Unchained also supports transfer-on-death designations that bypass probate.

Nunchuk's approach is the most technically innovative. Its autonomous inheritance uses on-chain timelocks enforced by the Bitcoin network: after the timelock expires, the signing requirement drops automatically without any action from Nunchuk. This means inheritance execution works even if Nunchuk ceases to exist. Beneficiaries can receive keys directly, through a trusted guardian, or through a split arrangement where neither party has unilateral control.

For a deeper analysis of custody models and inheritance strategies, see our research on Bitcoin custody solutions compared and the Bitcoin inheritance planning guide.

Guided Custody vs DIY Multisig

The core tradeoff in collaborative custody is convenience versus sovereignty. Guided services like Casa, Unchained, and Nunchuk reduce the operational burden of multisig: they handle key health checks, provide recovery assistance, and guide non-technical heirs through inheritance. The cost is a recurring subscription and a degree of trust that the provider will behave honestly with their single key.

DIY multisig with Sparrow or Caravan eliminates all third-party dependencies. You hold every key, define every quorum, and answer to no one. The cost is operational complexity: you must manage your own backups, test recovery procedures, document everything for heirs, and stay current on Bitcoin Script changes that might affect your setup. A mistake in key storage or backup procedures can result in permanent loss of funds with no recovery path.

A practical middle ground exists: start with a guided service to learn multisig operations, then migrate to self-managed custody once you are comfortable with the key management workflow. Both Casa and Unchained publish recovery documentation that allows clients to exit without the provider's cooperation, and Caravan exists specifically as Unchained's open-source escape hatch.

Pricing Comparison

Cost structures vary significantly depending on the level of service, the number of keys in the quorum, and whether you need additional financial products.

Unchained's loans carry a 12% interest rate with a 2% origination fee and $150,000 minimum. Trading desk fees are 1.0% under $100K, 0.75% for $100K to $1M, and 0.50% above $1M. IRA transactions incur a 1.5% trading fee with a $2,000 minimum per transaction and $50,000 minimum investment.

How to Choose a Collaborative Custody Provider

If you want the simplest onboarding experience with strong anti-social-engineering protections and multi-asset support: Casa is the strongest option. Its mobile-first design and features like Guardian Mode and phone call detection make it well-suited for users who prioritize security UX.

If you need financial services beyond custody: Unchained is the only provider offering Bitcoin-collateralized loans, self-custodied IRAs, and a trading desk alongside collaborative custody. It is particularly relevant for high-net-worth individuals and businesses that want to use Bitcoin as a financial asset rather than simply store it.

If you want the most technically advanced multisig with on-chain inheritance: Nunchuk's Miniscript-based autonomous inheritance and Taproot multisig support represent the cutting edge of Bitcoin self-custody tooling. Its broad hardware wallet support and cross-platform availability (desktop and mobile) make it versatile for technical users.

If you want maximum sovereignty at zero cost: Sparrow Wallet gives you complete control over every aspect of your multisig setup, but you carry full responsibility for backups, recovery, and inheritance documentation. Use Caravan as a complementary recovery tool or as a lightweight alternative for simple multisig coordination in the browser.

Frequently Asked Questions

Can a collaborative custody provider steal my Bitcoin?

No. In a collaborative custody model, the provider holds only one key in a 2-of-3 or 3-of-5 multisig arrangement. Moving funds requires at least two keys, and the provider holds only one. The provider can co-sign transactions at your request but cannot initiate transfers unilaterally. This is the fundamental security guarantee of multisig: no single party controls enough keys to spend.

What happens if my collaborative custody provider shuts down?

You retain full access to your funds. In a 2-of-3 setup where you hold two keys, you can sign transactions independently without the provider's key. Casa publishes Sovereign Recovery Instructions for offline recovery. Unchained maintains Caravan as an open-source escape hatch. Nunchuk's on-chain timelocks automatically adjust signing requirements if the platform becomes unavailable. In all cases, your keys remain on your own hardware devices.

Is collaborative custody better than a single hardware wallet?

For significant amounts of Bitcoin, multisig provides meaningfully stronger security than a single signing device. A single hardware wallet creates a single point of failure: if the device is lost, stolen, or compromised, funds are at risk. Multisig distributes that risk across multiple keys in separate locations. Collaborative custody adds a recovery backstop without sacrificing self-custody, since the provider cannot spend funds alone.

How much Bitcoin should I have before using collaborative custody?

There is no strict threshold, but the cost-benefit calculation matters. At $120 to $250 per year for entry-level tiers, collaborative custody makes practical sense once your holdings exceed roughly $10,000 to $50,000. Below that, a single hardware wallet with a properly secured seed phrase backup may be sufficient. The decision also depends on your technical comfort level: if you are not confident managing recovery procedures alone, guided custody is valuable at any amount.

Can I use collaborative custody for a Bitcoin IRA?

Unchained is currently the only provider offering a self-custodied Bitcoin IRA. Traditional Bitcoin IRAs require a third-party custodian to hold the private keys on your behalf. Unchained's IRA uses the same 2-of-3 multisig model as its standard vaults, meaning you hold two of three keys even within the IRA structure. Setup costs $995 (which includes the first-year account fee), with $250/year ongoing and a 1.5% trading fee on IRA transactions.

What is the difference between collaborative custody and a managed multisig?

The terms are often used interchangeably, but there is a meaningful distinction. Collaborative custody specifically refers to arrangements where the user holds the majority of keys and the service provider holds a minority. A managed multisig could describe any multisig arrangement, including institutional setups where the custodian holds the majority of keys. The critical question is always who holds enough keys to spend: in true collaborative custody, the user does.

Does collaborative custody work with Taproot?

Support is emerging. Taproot multisig using Schnorr signatures and MuSig2 offers privacy advantages because multisig transactions look identical to single-sig on-chain, reducing fees and improving fungibility. Nunchuk launched a Taproot multisig wallet in beta in 2026. Sparrow Wallet supports P2TR for single-sig and is tracking multisig Taproot standards. Casa and Unchained still use traditional P2WSH multisig as of mid-2026.

This tool is for informational purposes only and does not constitute financial advice. Pricing, features, and availability are based on publicly available information and may change. Always verify current details directly with each provider before making custody decisions.