Found a Casascius Coin? Value, Redemption and What UK Executors Should Do

By Simon Bumford, Founder · 2026-09-07 · 19 min read

A sealed Casascius coin can be worth six figures and anyone who peels it controls the bitcoin. How to check it, value it, tax it and handle it in a UK estate.

The short version

A Casascius coin is a brass, silver or gold-plated disc, made between 2011 and 2013, with a bitcoin private key sealed under a hologram on the back. While the hologram is intact, whoever holds the coin controls the bitcoin. Peel it and the bitcoin can be moved, but the coin becomes a shell, and the collector premium that sealed coins carry, which at recent auctions has ranged from a few percent to well over half again on top of the bitcoin inside, is gone for good. If one has turned up among a relative's possessions, three things are true at once. It may be worth a great deal: in June 2026 a single 25 BTC coin was redeemed for about $1.78 million, and on 7 September 2026 the public tracker showed 17,437 coins and bars still sealed, holding 34,571 BTC between them. It is a bearer asset, so the first person to sweep the key wins, whether or not they are the rightful heir. And English law has never had to decide a case about one, HMRC has published nothing on how to value one, and most UK executors will never have seen one. This guide covers how to tell whether a coin is real and still loaded without touching the hologram, what it is worth and why that is two numbers rather than one, how to value it for inheritance tax, what an executor's duties require, how to redeem one safely if that is the right decision, and what to do with the other physical bitcoin products an estate might contain. It is written for England and Wales. Nothing here is tax or legal advice for a specific estate; the sums involved justify a professional.

What a Casascius coin is

Mike Caldwell, a software engineer in Sandy, Utah, announced the first coins on the Bitcointalk forum on 6 September 2011: a 1 BTC brass coin selling for 1.25 BTC, with "a private key" under the hologram and "the first 8 characters of the bitcoin address" printed on the outside. Over the following two years the range grew to half, one, five, ten and twenty-five bitcoin coins, silver rounds, gold-plated bars of 100, 500 and 1,000 BTC, and a one ounce gold 1,000 BTC coin, of which the Bitcoin wiki records that only a handful were made. In total roughly 28,000 items were sold, loaded with about 91,000 to 99,000 BTC depending on how the two public trackers count unfunded and later-funded pieces. The design was simple. Caldwell generated a key pair, printed the private key in a compact "minikey" format on a slip of paper, sealed it under a tamper-evident hologram, and funded the public address. The coin's own FAQ states that he did not keep the keys. Removing the hologram exposes what the site calls an "obvious honeycomb tamper evident pattern" that cannot be concealed, so a coin is either visibly intact or visibly opened. It ended in November 2013. A letter from FinCEN, the US financial crimes regulator, took the view that loading coins with bitcoin made Caldwell a money transmitter; he told Reason it arrived just before Thanksgiving and had cost him $5,000 in legal fees within a fortnight. His site still carries the notice: "As of Nov 27, 2013, I suspended sales of items that contain digital bitcoins." Everything sold after that date is empty. The loaded coins in circulation are the ones from those two years, and they have never been replaced.

First, do not peel it

Whatever else happens, nobody should touch the hologram until the estate has decided what to do. Two reasons. The first is value. A sealed coin sells to collectors for more than the bitcoin it contains, sometimes a little more, sometimes a great deal more. A redeemed coin is a curiosity worth a few thousand dollars at most. Peeling converts the first into the second in one motion and cannot be undone. An executor who peels a coin that would have sold sealed for 40% above its bitcoin content has destroyed that 40%, and the duty to preserve the estate's assets is not a formality. The second is safety. The moment the key is exposed, anyone who sees it can sweep the bitcoin, and the transaction is irreversible. The best documented redemption of a large item, a 100 BTC bar peeled by its original buyer in May 2025, is instructive. He swept about $10 million of bitcoin successfully, then discovered that a stranger had taken the Bitcoin Cash that sat on the same key, worth roughly $40,000, minutes before he could, because he had posted an image of the key online. He described the experience to Cointelegraph as feeling like "destroying a piece of history". An executor handling a coin they do not understand, in front of family members, is at more risk than an experienced holder was. So the order is: identify, verify, value, decide, and only then, if the decision is to redeem, peel in private under controlled conditions. The rest of this guide follows that order.

How to check whether it is real and still loaded, without peeling

Every genuine coin shows the first eight characters of its bitcoin address, the "firstbits", on the outside: printed on the hologram on the 2011 series, visible through a small window on later ones. That is enough to identify the full address and check the balance on the public blockchain. Nothing about this step touches the seal. Type the firstbits into the Casascius Tracker or the Casascius Bitcoin Analyzer. Both list every known item with its series, denomination, status and balance, and link to a block explorer. A coin showing "Active" with the expected balance is loaded. A coin showing "Redeemed" has been emptied, whatever the hologram looks like. A firstbits that matches nothing is a warning. On 7 September 2026 the Analyzer showed 27,916 items tracked, 17,437 still active, 34,571.1 BTC unredeemed. Then look at the hologram itself. Genuine ones are intact, undistorted, and show no honeycomb pattern. Counterfeits exist: Caldwell published a warning about fake holograms in December 2013, noting a different typeface and B logo shape, and collectors have documented fakes on eBay with the wrong font, line depth and background pattern. A coin with a plausible hologram but no matching tracker record, or a tracker record showing the address was emptied years ago, is not what it appears to be. Two more things to record while you are there. First, which series it is: the 2011 coins carry a hologram misspelt "CASACIUS" and use a 22 character key; later ones use 30. Second, whether the address was funded before August 2017, because if so it almost certainly also holds Bitcoin Cash and possibly other forked coins on the same key, which is what the May 2025 redeemer lost. Photograph the coin's faces and the firstbits. Do not photograph anything under a hologram, ever.

What it is worth: two values in one object

A sealed Casascius coin has a floor and a market. The floor is the bitcoin inside at spot price, which anyone can realise by peeling. The market is what a collector will pay for the sealed item, and the gap between them is the premium. The premium is real and it is documented. At GreatCollections in November 2021 a 2011 25 BTC coin graded MS-67 sold for $1,698,750, about 3% over the bitcoin it held. At Heritage in November 2023 a collection of 250 small coins realised $7.2 million, with the best 1 BTC brass examples fetching $43,200 each against a spot value around $34,900, a premium near 24%. At Heritage in June 2025 a 2011 1 BTC coin graded MS-66 made $108,000 and a 0.5 BTC coin $54,000, both around 6% over spot; the same sale included an unfunded gold 1,000 BTC shell at $84,000, which shows what the object alone can command. At Stack's Bowers in June 2025 a 2013 brass 1 BTC coin set a record of $117,000, roughly $10,000 above face, and in June 2026 a silver 1 BTC coin made $88,450 against a spot price near $64,500, a premium of about 37%. Small, high-grade silver pieces have gone for two to three times face. The honest range, then, is from roughly nil to well over half again, with three regularities. Percentage premiums are larger on small denominations and shrink as the bitcoin price rises, because the collectible component does not scale with the coin's face value. Grade and provenance matter: nearly every six figure result above was a coin graded by PCGS or NGC. And the premium is not guaranteed; in the November 2023 Heritage sale a 0.5 BTC coin sold marginally below its bitcoin content. Redeemed shells are a different market entirely. A peeled 5 BTC "Bitnickel" made $1,440 and a redeemed storage bar $4,320 at Stack's Bowers in 2023. Graded redeemed coins do sell, but in the low thousands of dollars. That gap, between six figures sealed and low thousands peeled, is the number an executor is responsible for. There is no UK auction house with a published track record in these items. The market is Heritage, Stack's Bowers and GreatCollections, all American, and buyer's premiums run above 20%, which matters when comparing hammer prices to what an estate would net.

The coin, the key and the bitcoin are three different things

It helps to be precise about what an estate actually owns, because the law is. The metal disc is a chattel, an ordinary item of personal property that passes under the will like a watch. The bitcoin is not in the coin; it is a balance recorded on a public ledger, and since the Property (Digital Assets etc) Act 2025 took effect on 2 December 2025 it is expressly capable of being property in its own right, in a third category that is neither a physical thing nor a debt. The private key under the hologram is neither of those; it is information that gives whoever reads it the ability to move the bitcoin. The High Court drew exactly this distinction in Howells v Newport City Council in January 2025, the case of the man whose hard drive holding the key to about 8,000 BTC went to landfill in 2013. The judge held that the council owned the physical drive, that the bitcoin was property but "not tangible property and cannot be on the hard drive or in the landfill", and that the private key was "information, not property". The claim failed. The reasoning applies directly to a coin: the estate owns the disc, the estate owns the bitcoin, and the seal is what keeps those two facts aligned. The Law Commission, whose work led to the 2025 Act, put the principle in a sentence: a crypto token is a thing "different from the physical medium on which that information is recorded". No English court has yet had a physical bitcoin coin in front of it, and the Commission's reports did not analyse one. The safe formulation for an estate is two distinct assets, physically bound together by a sticker.

Valuing it for inheritance tax

Inheritance tax is charged on the open market value of the estate's property at the date of death, under section 160 of the Inheritance Tax Act 1984: "the price which the property might reasonably be expected to fetch if sold in the open market at that time". For a sealed coin that is the collector price, not the bitcoin price, because a willing buyer in the open market for these items pays the premium. HMRC's own manual says that for household goods and collections, "sales after the death, particularly those at auction, provide the best evidence of the open market value", that insurance valuations are not acceptable, and that coin collections should be referred to its Shares and Assets Valuation team. Its guidance on the hypothetical market also explains that a single special buyer willing to pay over the odds is discounted, but a market of many collector bidders is simply the market. HMRC has published nothing on physical bitcoin, Casascius coins or a collector premium. Its inheritance tax page in the Cryptoassets Manual says only that cryptoassets are treated like other estate assets, that the date of death value must be given, that inaccessible assets should be explained in the additional information box of the IHT400, and that unlike shares and land they do not qualify for loss on sale relief. What follows is an application of the general rules, not HMRC's stated view. A defensible approach is to obtain a written professional valuation of the sealed coin as a collectable, instructed to give open market value at the date of death, and to record separately the bitcoin content at that date from a named exchange price. Report the coin either as a collection on schedule IHT407, whose box 3 covers "collections of coins", at its full sealed value, or split the numismatic value there and the bitcoin at box 76 of the IHT400, which since the April 2026 edition reads "other assets including cryptoassets". Whichever route, explain the coin, the address, and the method in the additional information box, and do not count the bitcoin twice. The nil rate band is £325,000, frozen to 2031, and the rate above it is 40%, so a single loaded coin can be the difference between an estate that pays no tax and one that does. Our guide to inheritance tax on cryptoassets and the calculator cover the wider position.

What an executor's duties require

Personal representatives must "collect and get in" the estate and administer it according to law, under section 25 of the Administration of Estates Act 1925, and they owe the statutory duty of care in the Trustee Act 2000 to exercise "such care and skill as is reasonable in the circumstances". An executor who destroys value through carelessness can be personally liable for the loss. For a sealed coin, that translates into a short list. Secure it. A coin worth six figures that anyone can redeem by peeling a sticker should not sit in a drawer while probate runs. A bank safe deposit box or a solicitor's strong room is appropriate, and the estate can insure it; the power to insure trust property applies to personal representatives. Keep it sealed unless and until a decision to redeem is properly made and recorded. Given the auction evidence, peeling without a valuation is hard to defend. Value it properly. Ask a specialist auction house with a record in these items for a written opinion, or a UK valuer who will consult one. Ask for open market value at the date of death, and ask them to state the bitcoin content separately. Record everything: the firstbits, the tracker record, photographs of the exterior, the valuation, and the decision trail. If the family does not know the coin exists or where it is kept, that is precisely the gap our guide for executors handling crypto and probate checklist are written to close. Decide between the routes. Selling sealed realises the premium and avoids the heir ever handling a key. Distributing the coin in specie to a beneficiary who wants to keep it is the simplest outcome if the will allows. Redeeming and distributing the bitcoin is the third option, and the one that needs the most care.

If the decision is to redeem: doing it safely

Redemption means peeling the hologram, reading the key, and moving the bitcoin to a wallet the estate or heir controls. The key is in Casascius's minikey format: a short string beginning with "S", 22 characters on the 2011 coins and 30 on later ones. It is not the format most modern wallets expect, and that is where people go wrong. Use a wallet that accepts minikeys directly and offers a sweep, not an import. Electrum handles minikeys natively, describing them in its own code as "widely used in Casascius physical bitcoins", and its sweep function moves the entire balance to a new address in one transaction. Sparrow, popular though it is, accepts only standard WIF keys and will reject a minikey unless it is converted first. Bitcoin Core cannot import minikeys at all. Sweeping matters because importing a key into a wallet and then spending part of the balance leaves the remainder on the original address, where anyone who later reads the coin can take it; the Bitcoin wiki's paper wallet page records this mistake as a common cause of loss. Do it on a clean, offline or freshly set up machine, in private, with nobody photographing anything. Never type the key into a website; converters and "checkers" online are exactly where stolen keys go. Send a small test amount first if the sum justifies the fee, then sweep the rest, and confirm the new balance on an explorer before anything is written down. If the coin was funded before August 2017, sweep the Bitcoin Cash on the same key with a separate wallet immediately afterwards, because someone else will otherwise. Our guides to backing up a hardware wallet and seed phrase storage cover where the swept bitcoin should live afterwards. Redemption is not itself a taxable disposal; moving bitcoin between addresses the same person controls is not a disposal under HMRC's rules. The tax consequences come when the bitcoin is sold, and they differ from selling the coin sealed.

Capital gains tax after probate

Whoever inherits acquires the asset at its probate value under section 62 of the Taxation of Chargeable Gains Act 1992, so the inheritance tax valuation becomes the base cost. What happens next depends on which asset is sold. Selling the sealed coin to a collector is a disposal of a chattel. The £6,000 chattels exemption in section 262 applies in principle, with marginal relief above that, and HMRC's manual confirms that coins which are not legal tender are chattels for this purpose; bitcoin is, in HMRC's stated view, not currency at all, so the exclusion for currency does not bite. In practice a loaded coin will exceed £6,000 and the relief will be small. The gain is the sale price less probate value, taxed at 18% or 24% for an individual, or a flat 24% if the personal representatives sell it during administration, per the current rates, with a £3,000 annual exempt amount. Redeeming and selling the bitcoin is a disposal of an intangible cryptoasset, with no chattels relief, taxed at the same 18% or 24%, and pooled with any other bitcoin the heir holds. From 1 January 2026 UK exchanges report customer transactions to HMRC under the Cryptoasset Reporting Framework, so a sale through a UK platform is visible. HMRC has never said how the probate value of a sealed coin should be split between the metal and the bitcoin once they are separated; a just and reasonable apportionment, documented, is the defensible approach. A loaded coin that has risen in value since death can therefore produce a real tax bill on the heir, and which asset is sold, and by whom, changes the number. That is a conversation for an accountant before anything is peeled.

Other physical bitcoin an executor might find

Casascius was the first and remains the most valuable, but it was not the only one. Several later products work the same way and some do not. Lealana coins, made in Hawaii from 2013, use the same hologram and firstbits approach, but some carry a BIP38 encrypted key that needs a separate passphrase; the maker's website no longer resolves. Titan Bitcoin coins, from 2014, may have depended on a registration and code system run through the maker's site, which has been offline since 2020; redemption is uncertain. BTCC Mint titanium coins, 2016 to 2018, were funded directly from mining rewards and have an unofficial public tracker; the mint closed in 2018. Denarium coins, from Finland, 2015 to 2020, use a minikey under a hologram and the maker's lookup service still works. All of these funded before August 2017 also carry Bitcoin Cash. Opendime, still sold by Coinkite, is a USB stick that generates its own key; the maker's instructions are to push a pin through a marked hole to reveal the key, irreversibly, after which it is swept like any other. Ballet cards, still sold, combine an encrypted key on the card with a passphrase under a scratch-off; both are needed. Tangem Note cards, discontinued, hold the key in a chip that never reveals it, so the bitcoin is moved by tapping the card against a phone running the maker's app, which Tangem says still works for every card sold; a damaged card is unrecoverable. Satori coins, Japanese poker chip style tokens of 0.001 BTC each, have a community registry showing 46,178 of 50,500 still loaded. Paper wallets, printed keys and QR codes popular from 2011 to 2016, are the commonest find of all and the most dangerous to handle, because the key is in plain view; the rules on sweeping rather than importing apply exactly. Steel plates stamped with words are not bearer items but backups of a seed phrase, usually the first four letters of each of twelve or twenty-four words, which restore a whole wallet when entered into wallet software. And most "physical bitcoins" that turn up are none of these. They are novelty tokens, sold for a few pounds, with no hologram, no firstbits and nothing inside. If there is no address on it and no tracker record, it is a paperweight.

Physical bitcoin is the inheritance problem in miniature

A Casascius coin is what every crypto inheritance looks like when it goes wrong: an asset whose existence the family may not know about, whose value is invisible from the outside, and whose control passes to whoever physically finds the key first. The reason a sealed coin is such a clean case is that the key, the location and the asset are all in one place. That is what makes it valuable to a collector and dangerous in a house clearance. The lesson generalises. A workable plan does not need to expose any key. It needs to record that the asset exists, roughly what it is, and where control of it sits, so that an executor knows to look for a coin in a safe rather than let it go to a car boot sale. Our crypto inheritance checklist sets out what to document and what never to write down, and the bitcoin inheritance guide covers the wider process. The two minute Bitcoin Inheritance Readiness Scorecard is a quick way to see whether your own arrangements would survive a stranger finding a coin in a drawer. Bitzo exists to make that documentation and verification happen in advance, through a non custodial process in which no key is ever handed over and the people who will need to act have been identified and verified beforehand. That is the difference between an heir who finds a coin and does not know what it is, and one who finds it with a note saying what it is, what not to do, and whom to call. The inheritance planning page explains how it works.