Somewhere between 3 and 4 million Bitcoin are permanently inaccessible. Not stolen. Not seized. Lost — because the people who held the private keys died, and nobody else had them.
That is roughly 15–19% of all Bitcoin that will ever exist. Gone. Not temporarily frozen in a probate dispute or locked behind a court order. Gone in the way that only Bitcoin can be gone: permanently, irreversibly, with no institution to petition and no reset button to press.
I am a California-licensed attorney (Bar #343622) and a solo Bitcoin miner. I run an Avalon Q ASIC on solar power. I operate a full node. I hold my own keys. And I have watched otherwise intelligent people — people who understood Bitcoin well enough to acquire and hold it — fail to answer a single question: What happens to this when I die?
Bitcoin Is Not Like Any Other Asset You Own
When most people think about estate planning, they think about bank accounts, real estate, brokerage accounts, maybe a life insurance policy. These assets share a common feature that is so fundamental we rarely even notice it: they all have institutional custodians.
Your bank holds your cash. Your brokerage holds your securities. The county recorder maintains your property records. When you die, your executor contacts these institutions. They present a death certificate, letters testamentary, and maybe an affidavit. The institution verifies, processes, and transfers. The system works because the system has a counterparty — an institution that recognizes legal authority and acts on it.
Bitcoin has no counterparty.
If you hold your own keys — which is the entire point of Bitcoin — there is no bank to call. There is no customer service line. There is no “forgot password” link. The Bitcoin network does not recognize death certificates, court orders, or letters testamentary. It recognizes one thing: a valid cryptographic signature produced by the private key that controls the UTXO.
If your heirs do not have that key, the Bitcoin does not move. Not now. Not ever.
The Permanent Loss Problem
This is not a hypothetical risk. It has happened thousands of times, and the losses are staggering.
Gerald Cotten, the founder of the Canadian exchange QuadrigaCX, died in 2018 while traveling in India. He was reportedly the sole person with access to the exchange’s cold storage wallets. Approximately $190 million in customer cryptocurrency became inaccessible. A court-appointed monitor later determined that much of those funds had been misappropriated before his death, but the access problem was real and devastating regardless.
Matthew Mellon, the banking heir and early XRP investor, died in 2018 with an estimated $500 million in cryptocurrency. He had reportedly distributed his private keys across multiple locations and security deposit boxes, but the recovery process was extraordinarily complex and the full extent of what was recovered has never been publicly confirmed.
These are the high-profile cases. For every one that makes the news, there are thousands of ordinary holders — people with 0.5 BTC, 2 BTC, 10 BTC — who die without telling anyone where the keys are. Their families do not even know the Bitcoin exists, let alone how to access it.
Chainalysis estimated in 2020 that approximately 3.7 million BTC were lost. Other analyses have put the figure between 2.8 and 4 million. The exact number is unknowable because lost Bitcoin looks identical to Bitcoin held by an extremely patient holder. But the scale is clear: a significant fraction of all Bitcoin that will ever exist has already been permanently removed from circulation because the humans who controlled the keys are no longer alive.
What Happens When There Is No Plan
Let me walk through the most common scenario I encounter. A Bitcoin holder dies. They had a will, maybe even a trust. The estate planning documents say something generic about “digital assets” — a catch-all phrase their attorney included because they read an article about it. Here is what typically happens next:
Step 1: The family discovers the Bitcoin exists. Maybe. If the holder mentioned it, or if the executor finds a Coinbase account during the email review, or if someone notices a hardware wallet in a desk drawer. Many families never get past this step. They simply do not know.
Step 2: The family has no idea what to do with it. They hold a Ledger or Trezor device. They do not know the PIN. They do not know what a seed phrase is. They do not know whether the 24 words written on a piece of paper in the safe are important. (They are. Those words are everything.)
Step 3: The family contacts the estate planning attorney. The attorney — with all due respect to my colleagues — typically has no idea how to handle self-custody Bitcoin. The attorney knows how to file a Heggstad petition, how to fund a trust, how to deal with the county assessor. They do not know how to derive a master private key from a BIP-39 mnemonic phrase, and they should not be expected to.
Step 4: The Bitcoin sits. Weeks become months. Months become years. The hardware wallet is in a drawer somewhere. The seed phrase backup, if it exists, is in a safe nobody checks. The value fluctuates — irrelevantly, since nobody can touch it anyway. Eventually, the knowledge of where the backup is stored fades. Someone throws out the “weird USB thing.” The piece of paper gets lost in a move.
Step 5: The Bitcoin is gone.
This sequence is not rare. It is the default outcome when a self-custody Bitcoin holder dies without a specific, technical, tested plan for inheritance.
Why Standard Estate Planning Fails Bitcoin
A will distributes assets. A trust avoids probate and provides management instructions. A power of attorney authorizes someone to act on your behalf during incapacity. These are essential documents. Every adult should have them.
But none of them solve the Bitcoin problem, because the Bitcoin problem is not a legal problem. It is a technical access problem wrapped inside a legal one.
Your will can say “I leave my Bitcoin to my daughter.” Beautiful. Now how does your daughter access it? Does she know what a hardware wallet is? Does she know where the seed phrase backup is stored? Does she know which derivation path you used? Does she know whether the wallet uses a passphrase (the so-called “25th word”)? Does she know the difference between a native SegWit address and a Taproot address? Does she know how to verify that she is looking at the right wallet before she moves anything?
If the answer to any of those questions is no, then your will — no matter how beautifully drafted — is insufficient.
The legal documents create the authority to act. But authority without access is meaningless when the asset has no custodian. You cannot petition the Bitcoin network. You cannot subpoena a blockchain. You cannot get a court order compelling a decentralized protocol to hand over funds.
What a Proper Bitcoin Estate Plan Actually Looks Like
A real plan addresses both sides: the legal authority and the technical access. Here is what that involves:
1. A Custody Audit
Before you plan for inheritance, you need a clear picture of how your Bitcoin is currently held. Where are the funds? On an exchange? In a single-signature hardware wallet? In a multisig setup? Each custody model has different inheritance implications. An exchange account is relatively simple — your executor contacts the exchange with a death certificate. A 2-of-3 multisig with geographically distributed keys is secure and recoverable, but only if someone knows the configuration.
2. A Technical Access Document
This is the document most estate plans are missing entirely. It is a step-by-step guide — written for a non-technical person — that explains exactly how to access and transfer the Bitcoin. It covers:
- What devices and software are involved
- Where backup materials are stored (and how to access those locations)
- What the seed phrase is and how to use it for recovery
- Whether a passphrase is in use (and what it is, stored separately from the seed phrase)
- How to verify balances before moving anything
- How to execute a transfer to the heir’s wallet or to an exchange for liquidation
This document must be physically secured. It must be updated when your custody setup changes. And it must be tested — ideally by having the intended heir or executor walk through the process while you are alive to supervise.
3. Proper Legal Documents
Your trust or will should specifically address digital assets, but not with boilerplate language. It should reference the technical access document, designate a digitally competent executor or trustee (or a co-trustee with technical competence), and include provisions for the unique characteristics of cryptocurrency — including the irreversibility of transfers and the importance of securing private key material during the administration period.
4. A Security Architecture That Survives You
If your security model depends on you being alive, it is not an estate plan. A single-signature wallet with one seed phrase backup in your safe is secure while you are alive and devastating when you are not. Multisignature configurations — 2-of-3, 3-of-5 — allow you to distribute key material across trusted parties and locations so that no single point of failure can cause permanent loss. This is not just good security practice. It is the foundation of any serious Bitcoin inheritance plan.
5. Incapacity Planning
Death is not the only risk. What happens if you are incapacitated — a stroke, an accident, a cognitive decline? Your Bitcoin is not going to pay your medical bills by itself. Someone needs to be able to access it, and your durable power of attorney needs to actually authorize that person to manage digital assets and use the technical access materials you have prepared.
The Cost of Doing Nothing
I mine Bitcoin. I run a full node. I believe in self-custody as a fundamental principle. But self-custody carries a responsibility that most holders have not confronted: you are your own bank, which means you are also your own single point of failure.
If you hold Bitcoin and you have not built a plan that bridges the gap between your legal documents and the technical reality of accessing your keys, then you are one accident away from permanently destroying your family’s inheritance.
The Bitcoin does not care about your intentions. It does not care that you meant to tell your wife about the seed phrase. It does not care that you were going to set up multisig next month. The protocol enforces its rules with mathematical indifference. No key, no Bitcoin. No exceptions.
Every year you wait is a year your family spends unprotected from permanent, irreversible loss.
Start Here
I built a Bitcoin Inheritance Kit specifically for self-custody holders who understand the stakes but have not yet built the bridge between their Bitcoin security and their estate plan. It includes the custody audit framework, the heir letter template, the executor technical guide, and the Shamir’s Secret Sharing guide for distributing backup material securely.
If you hold your own keys, you need this. If you are not sure where to start, download the kit and start there. If your situation is complex — significant holdings, multiple custody arrangements, blended families, business entities — book a consultation and we will build something specific to your setup.
Your Bitcoin is only as permanent as your plan to pass it on.
Asaf Fulks is a California-licensed attorney (Bar #343622), solo Bitcoin miner, and full node operator. He advises self-custody Bitcoin holders on estate planning, inheritance structures, and digital asset security. Learn more at asaffulkslaw.com.