A bitcoin does not look like anything: it has no physical form. It is an entry on Bitcoin’s public ledger, the blockchain. What a holder actually sees is text that points at that entry: an address, such as one beginning bc1, a private key that controls it, and usually a 12- to 24-word recovery phrase that backs the key up.
That is the evergreen answer, and it does not change with the market. The rest of this piece shows what each of those pieces looks like, why a “physical bitcoin” is only a carrier for one of them, and where HMRC says a thing with no location is located.
What does a bitcoin look like on a computer?
Nothing on your laptop or phone is the bitcoin. A wallet holds keys, and the coins stay on the shared ledger. Here is what each part looks like, drawn from the Bitcoin Improvement Proposals and the maker’s page cited below.
| What you see | What it looks like | What it does |
|---|---|---|
| Address | In the bc1 format, a lowercase string of at most 90 characters | Where coins are sent; safe to share |
| Private key | A secret number linked mathematically to the address | Spends the coins; never share it |
| Recovery phrase | 12, 15, 18, 21 or 24 ordinary words from a fixed list | Rebuilds the keys if the device is lost |
| Ledger entry | A record on the public blockchain | The bitcoin itself |
| Physical coin | Metal coin with a private key under a hologram | A carrier for a key, not the coin |
What does a bitcoin address look like?
The bc1 address format is defined in BIP-173, which this desk read on 31 October 2026. A Bech32 string has a human-readable part, the separator 1, and a data part, and runs to at most 90 characters. For Bitcoin’s main network the human-readable part is bc, chosen because it is shorter than btc. Encoders must output all lowercase, and mixed case is rejected.
So a mainnet address looks like this, the test vector printed in BIP-173 itself and not anyone’s wallet: bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4.
What does a seed phrase look like?
It looks like a short list of unrelated words. BIP-39 calls it a mnemonic sentence, “a group of easy to remember words”, used to generate deterministic wallets. Its table, read on the same day, runs from 128 bits of entropy (12 words) to 256 bits (24 words). The words are stretched into a seed with 2048 rounds of HMAC-SHA512, and the wallet generates its keys from that seed. Anyone who reads your words can rebuild your keys, which is why setting a wallet up (our UK walkthrough) is mostly about where the words are kept.
Is there a physical bitcoin?
There are physical objects that hold bitcoin keys, and the maker of the best-known ones is clear about the difference. Casascius’s own site says the private key sits on a card inside the coin under a tamper-evident hologram that leaves a honeycomb pattern if peeled, and that the eight-character code on the outside is the first eight characters of the coin’s address. The digital bitcoin, it says, is on the public block chain and inaccessible unless that key is loaded into a wallet. The same page says that as of 27 November 2013 it suspended sales of items containing bitcoins.
Where is a bitcoin located for UK tax?
This is where the UK view adds something the ranking pages we read lack. Of the three pages read for this query, a Reddit thread, BBC Bitesize and a coin dealer’s blog, none cites HMRC on where a bitcoin is, in the text we could read.
HMRC’s CRYPTO22600, read on 31 October 2026 (published 30 March 2021, updated 28 November 2025), says cryptoassets are digital and “do not have a physical location”, yet their location, or situs, still has to be fixed for tax. It is guidance, not statute. HMRC’s view is that the statutory location rules in the Taxation of Chargeable Gains Act 1992 do not apply to an exchange token distinct from any underlying asset, and that its location is “determined by the residency of the beneficial owner”.
The consequence, per the manual: a UK resident under the Statutory Residence Test is liable to UK tax on a taxable transaction with their tokens. On that view, the exchange’s country or the drawer holding a hardware wallet does not decide where the bitcoin is; the owner’s residence does. Co-owned tokens follow section 275C, each owner’s share sitting where that owner lives. For Inheritance Tax there are no statutory rules and general principles apply. Amounts are counted in satoshis, and cashing out to a bank has its own UK tax step.
Questions readers ask
What does real Bitcoin look like?
Real bitcoin has no appearance of its own. It exists as entries on the public ledger, and what anyone can show you is the text that points at those entries: an address, such as one beginning bc1, a private key, or a 12- to 24-word recovery phrase. Pictures of gold coins with a B on them are illustrations or collectables, not the asset.
Is a physical bitcoin a real bitcoin?
Only in the sense that it carries a key. Casascius, a maker of collectable coins, says on its own site that the digital bitcoin sits on the public block chain and is inaccessible unless the private key inside the coin is loaded into a wallet. The metal and hologram are packaging. Anyone who has the key can move the coins, whoever holds the metal.
What exactly is Bitcoin (BTC)?
Bitcoin is a digital asset recorded on a shared public ledger, the blockchain, with no physical form. BTC is the shorthand for one unit, which divides into smaller units called satoshis. For UK tax, HMRC’s manual describes exchange tokens as a new type of intangible asset, and on its view one is located where its beneficial owner is resident, not where a server sits.
Worth saying plainly: knowing what a bitcoin looks like is not knowing its risk. Crypto assets are high risk, a lost recovery phrase can mean a lost holding, and nothing here is advice. Your tax position is a question for HMRC or a qualified adviser.