KoinlyticsThis is not legal or tax advice. Estate law, probate procedure, and inheritance tax treatment vary by country and often by state or province within a country; consult a lawyer and a tax specialist in the jurisdiction that will handle the estate.
The problem nobody solves by accident
Self-custody works because access to the keys is access to the funds, full stop, with no institution able to intervene. That is also exactly what makes death and incapacity hard. A set of instructions detailed enough for a grieving spouse or a teenage child to recover funds is, by construction, detailed enough for anyone who finds that document to steal them. There is no version of "write down the seed phrase" that solves for the heir without also solving for the thief. The entire design problem is splitting the knowledge required for recovery across multiple people, multiple documents, or multiple points in time, so that no single point of failure has enough to act alone, while enough of the pieces reliably become available when they are actually needed.
Multisig with an heir holding one key
A 2-of-3 multisig setup, see multisig and Safe, splits signing authority across three keys where any two can move funds. One practical structure: the holder keeps two keys, an heir or executor holds the third, and normal spending requires the holder's two keys while recovery after death requires the heir's key plus one of the holder's, retrievable from a safe deposit box or similar. This avoids handing over full access while alive, and avoids a single point of failure. The tradeoff is complexity: the heir needs to understand how to use a hardware wallet and construct a multisig transaction, under stress, possibly years after last touching the setup. A structure only a crypto-native person can operate is not a functioning inheritance plan if the heir is not crypto-native.
Shamir-style seed splitting
Shamir's Secret Sharing splits a seed into N shares where any M of them reconstruct it, for example 3-of-5. Give shares to five different people or locations and any three, in any combination, recover the wallet. The failure modes are specific. A threshold set too high, 5-of-5, means one lost share destroys everything permanently, with no error message and no recovery path, because the math cannot reconstruct the secret from four of five parts. A threshold set too low, 2-of-5, makes collusion between two holders sufficient to steal the funds, which defeats the purpose of splitting it at all. And unlike multisig, most implementations are a one-time operation with no way to rotate or revoke a share if a holder becomes untrustworthy or a share is compromised; fixing that requires moving funds to a freshly split wallet, which needs the same coordination you were trying to avoid.
Timelocks and dead man's switches
A dead man's switch, whether a smart contract that releases funds to a named address after a period of holder inactivity, or a service that emails a seed phrase to a beneficiary if you stop checking in, sounds like it solves the coordination problem without involving other people. It does not solve it; it moves the maintenance burden onto a mechanism that has to keep working, unattended, for decades. A check-in interval set too short triggers false releases when the holder is on a long trip or simply forgets; set too long, and it fails to trigger for months after an actual death, during which the service, contract, or company running the mechanism can itself shut down, get hacked, or stop being maintained. A dead man's switch is software with the specific job of running correctly on a day nobody is watching it. That is a hard property to guarantee, and every year of delay before that day increases the odds something upstream has quietly broken.
The legal instrument is not the technical access
A will can name "all cryptocurrency holdings" as part of an estate and direct that they pass to a beneficiary, the same as it would a bank account or a house. What a will cannot do is contain the actual mechanism of transfer, because a will is not the transfer, it is an instruction to whoever administers the estate. For crypto, unlike a bank account, there is no institution the executor can present the will to and request access. The executor needs the keys directly, and the will naming the asset does nothing to provide them.
This creates a specific and often overlooked danger: putting the seed phrase itself inside the will. In many jurisdictions, a will becomes a public document once it is filed for probate, readable by anyone who requests the court record. A seed phrase, see seed phrase security, written into that document is exposed to the public at the moment of filing, permanently, often well before an heir has moved the funds. The correct pattern keeps the legal instrument and the technical access completely separate: the will states that crypto assets exist and who should receive them, while a private, non-probate mechanism, a letter held by a lawyer under seal, a safe deposit box, a multisig key, a Shamir share, actually enables the transfer.
Custodial accounts and exchange death procedures
Assets left on an exchange rather than self-custodied are procedurally closer to a bank account: most major exchanges have a documented deceased-account process requiring a death certificate, letters of administration or probate documentation, and identity verification from the beneficiary. This is slower and more bureaucratic than self-custody, often taking months, but it does not depend on any private key surviving intact or any heir understanding cryptography. The tradeoff between self-custody and custodial holding, already a live question during life, gets sharper at death: self-custody demands more advance planning and offers no institutional fallback if that planning fails.
The practical minimum
Below all of the above sits one document almost nobody writes: a plain instruction sheet, held separately from any actual secrets, that tells the executor or heir what exists and who to ask. Not the seed phrases, not private keys, just an inventory: which exchanges have accounts, which wallets exist and roughly what they hold, whether a multisig or Shamir scheme, see MPC and threshold signatures for a related approach used by some custody providers, is in place and who holds the other pieces, and the name of a technically capable person, a lawyer, a trusted friend, a service, who can guide the heir through recovery. Without this document, a technically correct multisig or Shamir setup is worthless, because nobody who survives you knows it exists at all.
Practical steps
Separate the legal instrument from the technical access: let the will name the assets and the beneficiary, and keep keys and seed phrases out of any document that becomes public in probate. Write the plain instruction sheet first, before building anything more elaborate; it is the single highest-value document and the one most people skip. If choosing multisig or Shamir splitting, test the recovery process now, with the actual people who would need to perform it, rather than assuming it will work when needed. Confirm with a local estate lawyer how crypto is treated for inheritance and estate tax purposes in the relevant jurisdiction, since this varies widely and changes over time. Koinlytics can give an heir or executor a clear read of what wallets hold across chains once they have access, but it holds no keys, cannot recover access on its own, and nothing in this chapter substitutes for legal advice.