Bitcoin Inheritance and Estate Planning

Why Inheritance Deserves Its Own Topic

• Bitcoin inheritance is not purely a tax question, nor purely a technical one. It is what happens where the two intersect. If the keys never reach the family, not a single satoshi can be moved — and yet, for tax purposes, the holding is still valued as property and can fall within the scope of inheritance tax.
• That asymmetry creates a difficulty other assets do not have. With a bank deposit or real estate, heirs can realise their rights through an institution — a bank, a registry office. With Bitcoin there is no counter to approach for someone who does not hold the keys.
• Our topic on Bitcoin taxes covers the basics of inheritance and gifts: that crypto is taxable, and how it is valued. This page picks up where that leaves off, dealing with the technical and procedural practicalities. Details of the tax regime itself stay with the tax topic.
• This page explains the rules and the practice as of August 2026, based on primary sources: the National Tax Agency, the Ministry of Justice, the courts, Diet proceedings, and published technical specifications. It is not individual tax or legal advice, and it does not recommend any particular provider or service.
• What the right sequence of steps looks like depends on family circumstances, the composition of the estate, and how the coins are stored. Confirm specific decisions with a tax accountant, lawyer, or judicial scrivener.

Crypto Assets as Inherited Property

• Item 4-1 of the National Tax Agency FAQ states plainly that where crypto assets are acquired from a decedent by inheritance, bequest, or gift, inheritance tax or gift tax applies. The Inheritance Tax Act reaches any property of economic value that can be measured in money.
• Valuation is covered by item 4-2. Crypto assets for which an active market exists are valued — by analogy to foreign currency — at the trading price published, as of the valuation date, by the crypto asset exchange service provider with which the taxpayer transacts. Where the taxpayer uses several providers, using the price of the one the taxpayer selects is acceptable.
• The "valuation date" here is the commencement of inheritance, meaning the moment of death. There is no softening device comparable to the monthly-average options available for listed shares, so a highly volatile asset is valued at a single point in time.
• The carried-over cost basis is easy to miss. For crypto assets acquired through a gift on death to an heir, through inheritance, through comprehensive bequest, or through a specific bequest to an heir, the acquisition cost is the amount valued, at the time of the decedent's death, under the valuation method the decedent had elected. In other words, the heir inherits the decedent's book value, not the market value at death.

• The consequence is that inheritance tax attaches to the market value at death, while any income on a later sale by the heir is measured from the decedent's acquisition cost. If the coins appreciated after the decedent bought them, the same unrealised gain is reached by both inheritance tax and income tax.
• For shares and real estate, the special rule adding inheritance tax to the cost basis of inherited property softens that overlap. But the National Tax Agency states explicitly that this rule applies only to capital gains income and cannot be applied to business income or miscellaneous income from transfers of shares and the like. Under the current regime, where crypto gains are classified as miscellaneous income, the softening does not operate.

When the Keys Never Reach the Family

• Taxation does not track whether the heirs can actually use the keys. In the House of Councillors Committee on Financial Affairs on March 23, 2018, the Deputy Commissioner of the National Tax Agency testified that even where an heir does not know the password set by the decedent, the heir succeeds to the crypto assets the decedent held, so those assets fall within the scope of inheritance tax.
• The reasoning given was that whether someone knows a password is a subjective circumstance that cannot be verified from outside, and excluding assets from taxation on that basis would be problematic from the standpoint of fairness in taxation. The practical tension of this whole topic is compressed into that exchange.
• So is there a technical route back when keys are lost? There is not. A private key is one number chosen from an astronomically large space of candidates, and searching for it by brute force is effectively impossible (our topic on why lost Bitcoin cannot be recovered treats the reasoning in detail).
• The exception is recovery assistance where an encrypted wallet file is still in hand and part of the password or its structure is remembered. That only works when the candidate space can be narrowed; it is powerless once the seed phrase itself is gone. Solicitations promising to "crack the wallet and recover your coins" are, in most cases, aimed at a second round of loss.
• There is little relief on the payment side either. National taxes are paid in money as a matter of principle, and inheritance tax alone permits deferred payment and payment in kind — but the property eligible for payment in kind is set out in ranks: first, real estate, ships, government bonds, local government bonds and listed shares; second, unlisted shares; third, movables. Crypto assets do not appear in that enumeration, and because they are not tangible things they are understood not to fall within "movables" either. If tax attaches to coins that cannot be moved, the cash must come from somewhere else.
• Renunciation of inheritance is an option, but it has a deadline. The petition must be filed with the family court for the decedent's last domicile within three months from the time the person knew that inheritance had commenced for them, and renouncing means succeeding to nothing at all, including the rest of the estate. This is a decision to make with professional involvement.

Lifetime Planning — Designing the Information

• Preparing for inheritance is, before it is any kind of tax structuring, an exercise in designing information. It begins with putting the family in a position to know what exists and where it is. If the very fact of ownership is unknown, no other preparation ever activates.
• The first artefact is an inventory of holdings: which exchange providers hold accounts, which wallets are in use (software or hardware), and roughly how much. Because amounts fluctuate, what matters is location rather than value.
• Next comes a set of access instructions: which wallet software, and what is used to restore, written so that someone without technical background can follow it. Writing the seed phrase itself into that same document turns the inventory into a single point of failure.
• The relationship to a will also needs sorting out. A will determines who succeeds to what; it is not the document for conveying how to gain access. Secrets written into a will become visible to heirs through inspection and the issuance of certificates.
• The storage system for handwritten wills, under which a Legal Affairs Bureau holds a self-written will, began on July 10, 2020. It can notify persons the testator designates upon death, and wills held under it are exempt from family court probate certification (Article 11 of the Act on Storage of Wills by Legal Affairs Bureaus).
• In practice the standard shape is a separation: the will fixes who succeeds, while the route to the keys is conveyed through a different channel. Both channels should be designed with professional advice suited to the family's circumstances.

Technical Options and Their Trade-offs

• Several technical approaches exist for breaking the state in which exactly one person knows the keys. This site recommends none of them, and sets out only the categories and the costs each one asks you to accept.

• Multisig distributes keys across yourself, family, or professionals, allowing a spend once a threshold is met. It lowers the chance that one loss costs everything, but it means nothing if no one understands the recovery procedure (the script-level machinery, such as P2SH and OP_CHECKMULTISIG, is covered in our glossary and Script primer).
• Timelocks create outputs that cannot be spent until a specified point, with OP_CHECKLOCKTIMEVERIFY, introduced by BIP-65, as the canonical example. Arrangements that let a backup key recover funds if one party becomes unavailable are a well-known use for this mechanism. The catch is that during your lifetime the arrangement must be rebuilt before each deadline arrives.
• SLIP-39 is a standard for splitting a seed into threshold shares for distribution. Because a single leaked share reveals nothing, more storage locations become viable — but wallet support is limited, and administering the shares is itself added work.
• What all of these have in common is that complexity is itself a risk. A scheme the family cannot understand can be more dangerous than a seed phrase written on paper. If you adopt one, the precondition is verifying, while you are alive, that another person can actually complete the recovery by following the instructions.

Inheriting an Exchange Account

• Crypto held with an exchange provider is a procedural problem rather than a key problem. The account is a contract with the provider, and heirs succeed to that contractual position and seek withdrawal or transfer on that basis.
• No statute, however, prescribes a single inheritance procedure common to all providers. The required documents, and the form of delivery — cash withdrawal in yen or transfer of the crypto itself — follow each provider's terms of service and guidance. This site does not walk through any particular provider's process.
• The general sequence looks like this.

• The balance certificate has a defined tax status. NTA FAQ item 4-2 states that the "trading price published by the crypto asset exchange service provider as of the valuation date" includes the trading price recorded on a balance certificate the provider supplies at the taxpayer's request.
• Industry self-regulation is handled by the Japan Virtual and Crypto assets Exchange Association (JVCEA), but so far as the association's published list of self-regulatory rules shows, no rule standardising the inheritance procedure itself appears there (as of August 2026). The places to check remain each provider's terms of service and support desk.
• Where an overseas provider was used, governing law, language, and identity verification requirements add friction. Domestic or foreign, everything rests on one precondition: that the family knows where the accounts are.

Self-Custody in Practice

• Under self-custody, what passes to the heirs is not an account but the ability to restore. The seed phrase, a passphrase if one is used, and the knowledge of which wallet software performs the restore only mean something when they arrive together.
• Distributing storage locations is effective against theft and disaster, but from an inheritance standpoint it tends to create a state where nothing can be restored unless every piece is found. A map of what was put where becomes a separate necessity.
• A BIP-39 optional passphrase demands particular care. If only the seed phrase is passed on, the intended wallet does not appear, and the family may look at an empty wallet and conclude that nothing was left.
• The realistic preparation is education more than technology. Have one trusted family member actually operate a hardware wallet and complete a restore once, using an amount you can afford to lose. Measured against its cost, it can be one of the more effective preparations available.
• At the same time, handing over key material during your lifetime creates a state in which that person can move the funds at any moment. Multisig and split storage are considered precisely because they let this trade-off between trust and safety be handled in stages.
• Note too that inheritance tax valuation requires a valuation-date trading price for self-custodied bitcoin as well. Because no third-party document like an exchange balance certificate is available, discuss with a tax accountant what evidence to preserve and how.

Corporate Holdings and Business Succession

• Where a company holds crypto assets, what passes on inheritance is not the crypto but the shares in that company. Key management remains a matter of the company's internal controls, outside the inheritance itself.
• A state in which only the founder knows the keys is, for a company, a gap in internal control. Withstanding a change of officers or a sudden absence presupposes structures such as signing by multiple people, separation of authority, and documented procedures.
• Year-end mark-to-market valuation under corporate tax, and the exceptions for self-issued crypto assets and crypto assets subject to specified transfer restrictions, are covered in our topic on Bitcoin taxes. Designing a business succession has to be considered together with corporate-specific questions such as share valuation and tax deferral schemes.
• Where crypto is held by a sole proprietorship, it is part of the individual's estate as a business asset. The routine work of segregating and recording it becomes, unchanged, the documentation used at inheritance.
• All of this presupposes the involvement of a tax accountant and a lawyer. This page does no more than indicate where the questions lie.

International Trends in Digital Estate Law

• Japan is not alone in having legal frameworks that lag behind digital estates. The direction of travel, though, is shared: jurisdictions are settling on treating accounts and data as inheritable. The representative frameworks are these.

• What distinguishes RUFADAA is the ordering of priority. Where a user has expressed intent through a provider's own designation tool, such as naming a legacy contact, that expression takes precedence over what a will says. A service's settings screen effectively functions as part of the estate plan.
• The German judgment held that a social network user contract passes to the heirs by universal succession, and that heirs may demand access to the account and the communications stored within it. It is known as a decision refusing to distinguish digital from analogue estates.
• Japan has no standalone statute equivalent to a "digital estate act." The matter is handled under the general principle of Article 896 of the Civil Code: heirs succeed, from the commencement of inheritance, to all rights and obligations belonging to the decedent's property, except those personal to the decedent.
• Yet every one of these frameworks establishes a right to demand access; none of them makes coins movable without keys. Law reaches accounts that a provider administers. It does not reach a Bitcoin private key that no one administers. That is the structural limit of what legislation can solve here.

Summary — What to Do While You Can, and the Deadlines

• To close, here is what can be done during your lifetime, listed roughly in descending order of impact. There is no need to do all of it at once.

• The deadlines matter too. The quasi-final income tax return is due within four months from the day after knowing inheritance commenced; the inheritance tax return and payment within ten months from the day after knowing of the death; renunciation of inheritance within three months from when the person knew inheritance had commenced for them. Inheritance tax also carries a basic exclusion of 30 million yen plus 6 million yen per statutory heir, which serves as the rough threshold for whether a return is needed at all.
• The rules are in motion. Under the amendment enacted in March 2026, income from transfers of crypto assets is reorganised as capital gains income, but the start of application is fixed as "January 1 of the year following the year in which the amended Financial Instruments and Exchange Act comes into force." That FIEA amendment was enacted and promulgated in July 2026, and the crypto provisions take effect on a date set by cabinet order within one year of promulgation — so application begins on January 1, 2027 at the earliest and, as a matter of law, no later than January 1, 2028 (as of August 2026 no cabinet order fixing the date has been promulgated; our topic on Bitcoin taxes covers the detail). Whether the reclassification brings the cost-basis-addition rule described above within reach of crypto assets is a question to revisit; no settled treatment has been published.
• What is technically possible and what is legally or fiscally required have to be designed separately. No professional can design your key arrangement for you, and no technology substitutes for tax and legal judgment. Both have to advance in parallel, while you are alive to do it.
• To repeat: this page explains the rules and the practice; it is not individual tax or legal advice. For the design of a specific estate, whether a return is required, and the preparation of documents, consult a tax accountant, lawyer, or judicial scrivener.