SimplB Vault is a multi-signature custody product designed for investors holding R500,000 or more in Bitcoin. It addresses a specific problem that exchange custody does not solve: how to hold a large Bitcoin position in a way that no single entity, including SimplB, can move unilaterally.
This article explains what multi-signature custody is, how SimplB Vault structures it, why it matters for large holdings, and what the trade-offs look like in practice.
| Scenario | What happens | Why it matters |
|---|---|---|
| Normal transfer | Client and SimplB co-sign | Bitcoin moves only with your consent |
| SimplB unavailable | Client and escrow provider co-sign | Access exists without SimplB |
| Estate transfer | Executor coordinates with SimplB and escrow | Bitcoin is recoverable after death |
| SimplB ceases | Client and escrow provider co-sign independently | Bitcoin never depends on SimplB’s existence |
What Multi-Signature Means
Multi-signature custody means that moving Bitcoin requires approval from multiple private keys held by different parties. The simplest structure is 2-of-2: two keys exist and both must sign. A more common institutional structure is 2-of-3: three keys exist and any two must co-sign for Bitcoin to move.
In SimplB Vault, the structure works as follows. You hold one key, SimplB holds another, and an independent third party (a key escrow provider) holds the third. To move Bitcoin, you and SimplB must both sign. SimplB cannot move it alone. You cannot move it alone. Only with both signatures does the Bitcoin move. This architecture eliminates single points of failure: if SimplB is hacked, the attacker only has SimplB’s key and would also need yours or the escrow provider’s to move anything.
How SimplB Vault Works
You control one key through a hardware wallet or a recovery phrase you secure personally. SimplB controls another key. An independent escrow provider holds the third. When you want to move Bitcoin out of your Vault, you initiate a transfer request through SimplB’s interface, SimplB generates a transaction requiring two signatures, you sign with your key, and SimplB signs with its key. The transaction is then broadcast to the Bitcoin network.
If SimplB is unavailable or uncooperative, you can work with the escrow provider instead. You and the escrow provider can jointly sign, and the Bitcoin moves without SimplB’s involvement. This recovery path is critical for scenario planning: if SimplB ceases operations or is acquired, you retain access through the escrow route regardless.
The multi-signature arrangement also creates a governance structure. You have veto power over every movement. SimplB cannot move the Bitcoin without your consent. That is fundamentally different from exchange custody, where the exchange controls the keys and you depend entirely on their policy not to move your funds.
Why Multi-Signature Matters for Large Holdings
For holdings under R500,000, exchange custody is generally appropriate. The risk of SimplB being hacked or misappropriating funds is low given SimplB’s FSCA licensing and institutional-grade security infrastructure, and the custody is adequate for the amount at risk.
For holdings over R500,000, the concentration risk becomes material. If SimplB holds all of your Bitcoin and SimplB is compromised, you lose everything. If SimplB becomes insolvent, your Bitcoin might be treated as a SimplB asset in a liquidation. A family office holding R50 million of Bitcoin cannot accept that risk profile. Multi-signature custody removes the single-entity concentration risk entirely: if SimplB is compromised, your Bitcoin is protected because the attacker only has one of three required keys. If SimplB becomes insolvent, your Bitcoin is not on SimplB’s balance sheet because you control one key and the escrow provider controls another.
Custody and Estate Access
A critical feature of SimplB Vault is the estate access protocol. If you die or become incapacitated, your executor or successor trustee needs to access the Bitcoin. With multi-signature custody, that access path is structured and documented in advance rather than improvised under pressure.
SimplB can work with your executor and provide the co-signature needed to move Bitcoin to an account controlled by the estate or successor trustee. The escrow provider can release their key to your executor through proper legal channels. The Bitcoin is recoverable and transferable to the next generation even without your direct involvement. This is fundamentally different from single-key self-custody, where a hardware wallet with an undocumented recovery phrase becomes permanently inaccessible after the owner’s death.
The Cost and Complexity Trade-Off
SimplB Vault is more expensive than standard exchange custody. There are custody fees, escrow fees, and potentially key management fees. For a R500,000 holding, the annual cost might be in the range of R5,000 to R10,000. For a R10 million holding, it might be R50,000 to R100,000. For most investors at these scales, that cost is justified by the security and governance benefits.
The complexity is also higher. You must manage a hardware wallet or recovery phrase and understand the multi-signature process. For investors who prefer simplicity, standard exchange custody is less demanding. For institutional investors and family offices, this level of active custody management is normal: it is how serious assets are administered.
Trust and Verification
With SimplB Vault, you can verify your Bitcoin holdings directly on the Bitcoin blockchain. You can see the multi-signature address that holds your Bitcoin, confirm it requires 2-of-3 signatures to move, and verify the balance. This verification is cryptographically certain. You do not have to trust SimplB’s claim that your Bitcoin exists.
This is different from traditional banking, where you receive a statement and trust the institution. With Bitcoin and multi-signature custody, trust is reduced to the Bitcoin network itself, which is globally distributed and cannot be compromised by any single entity.
How Access Works Across Scenarios
In normal operation, SimplB Vault is straightforward. You request a transfer, SimplB coordinates the signatures, and the Bitcoin moves. You do not need to think about the multi-signature mechanics in everyday use.
In a recovery scenario where SimplB is unavailable, you use the escrow provider’s key together with your own to move the Bitcoin. This requires coordination with the escrow provider and proof of identity, but the mechanism exists and is defined in advance, not improvised. In an estate scenario, your executor coordinates with SimplB and the escrow provider to move the Bitcoin to a new wallet controlled by the estate, presenting a death certificate and court documentation. In the worst case where SimplB ceases operations entirely, your Bitcoin is not trapped: you hold one key and the escrow provider holds another, which together meet the 2-of-3 threshold needed to move funds to any address you control.
Who Should Use SimplB Vault
SimplB Vault is designed for investors with holdings over R500,000 who want institutional-grade custody and governance. Family offices managing Bitcoin as a core asset benefit from the multi-signature structure, which aligns with fiduciary governance standards. Trusts holding Bitcoin across generations benefit from the estate access protocol, which ensures the Bitcoin is transferable on death or incapacity. Companies holding Bitcoin as a treasury asset benefit from the custody arrangement keeping Bitcoin off SimplB’s balance sheet and under the entity’s own control environment.
High-net-worth individuals who want to eliminate single-entity custody risk without taking on the full operational burden of pure self-custody are also well suited to the collaborative model. The structure provides self-custody without forcing the investor to manage every operational detail independently.
Who Might Not Need SimplB Vault
Investors with smaller holdings (under R500,000) can generally use standard exchange custody. The cost of Vault is not justified at that scale, and the operational complexity of managing a hardware wallet and escrow relationship adds overhead without proportionate benefit. Investors who prefer complete self-custody and are comfortable managing private keys and recovery phrases independently also do not need the collaborative layer that Vault provides. Investors who accept exchange custody risk and prefer simplicity over multi-signature governance are well served by standard custody arrangements.
The Broader Institutional Context
SimplB Vault is part of the infrastructure that allows Bitcoin to be integrated into institutional portfolios. Professional investors require custody that separates assets from the provider’s balance sheet, allows for governance oversight, and enables estate transfer. SimplB Vault provides that for Bitcoin in South Africa.
For family offices and institutions evaluating whether to hold Bitcoin, the existence of institutional-grade custody is a necessary condition. Without it, institutional investors cannot justify the holding to their boards or trustees. Good custody is not a detail: it is the precondition for serious allocation.
Frequently Asked Questions
What is SimplB Vault and how does it work?
SimplB Vault is a 2-of-3 multi-signature Bitcoin custody product for investors holding R500,000 or more. Three keys are created: you hold one, SimplB holds one, and an independent escrow provider holds the third. Any two of the three keys must co-sign for Bitcoin to move. This means SimplB cannot move your Bitcoin without your participation, and you have a defined recovery path through the escrow provider if SimplB is ever unavailable.
What is 2-of-3 multisig custody and why does it matter?
2-of-3 multisig means 3 private keys exist and any 2 must co-sign a transaction for it to be valid. No single key can move Bitcoin unilaterally. This eliminates the single point of failure that exists in pure self-custody (where losing one seed phrase means total loss) and in exchange custody (where the exchange holds all keys and failure means total loss). The structure distributes control without removing it from the investor.
Who holds the keys in a SimplB Vault arrangement?
The client holds one key via a hardware wallet or documented recovery phrase. SimplB holds one key through its own custody infrastructure. An independent third-party escrow provider holds the third key. To move Bitcoin in normal operation, the client and SimplB co-sign. If SimplB is unavailable, the client and the escrow provider can co-sign instead. No single party controls the Bitcoin on their own.
What happens to my Bitcoin if SimplB stops operating?
Your Bitcoin is not affected by SimplB’s operational status. You hold one key and the independent escrow provider holds another. Together, those two keys meet the 2-of-3 threshold required to move funds. You can transfer your Bitcoin to any address you control without SimplB’s involvement. The multi-signature architecture is specifically designed so that SimplB’s continued existence is not a dependency on your access.
What is the minimum holding size for SimplB Vault?
SimplB Vault is designed for investors holding R500,000 or more in Bitcoin. Below that threshold, the cost of custody fees and the operational complexity of managing a hardware wallet and escrow relationship is generally not justified relative to the assets under management. For smaller holdings, SimplB’s standard exchange custody arrangement offers adequate security with lower overhead.
Sources
- FSCA — Crypto Asset Regulatory Framework: FSCA licensing framework under which SimplB operates as a CASP (Crypto Asset Service Provider) for custody and brokerage
- SARS — Crypto Assets Tax Guidance: SARS guidance on the tax treatment of Bitcoin holdings, relevant to clients using SimplB Vault for long-term storage
- Bitcoin Optech — Multisignature (Multisig): technical explanation of Bitcoin multisignature arrangements including the 2-of-3 structure used in SimplB Vault
- Financial Intelligence Centre — FICA: FICA compliance requirements that SimplB meets as a licensed crypto asset service provider for vault clients
Want to secure your Bitcoin properly?
Book a Custody CallWritten by James Caw, Founder of SimplB. James has helped South Africans understand, buy and secure Bitcoin since 2015. SimplB operates as a Juristic Representative of CAEP Asset Managers, FSP 33933. Last updated: May 2026.
This article is for general educational purposes only and does not constitute financial, legal, tax or exchange control advice. The information reflects the regulatory position as at the date of publication. Your individual circumstances may differ and you should seek qualified professional advice before making any decisions.
