Bitcoin FAQ

Straight answers for people just starting and people who have held for years. If a word is new, check the glossary.

Getting started

What is Bitcoin?
A digital money network with no company, bank or government in charge. Thousands of computers (nodes) hold the same public record and check every new entry against the same rules. It launched in January 2009, a few months after Satoshi Nakamoto published the whitepaper on 31 October 2008.

Do I have to buy a whole bitcoin?
No. One bitcoin is 100,000,000 sats, so you can start with a small amount.

How many bitcoin will there ever be?
Just under 21 million. About 20.1 million exist already (blockchain.com, 31 Oct 2026). New coins come from mining, and the amount per block halves every 210,000 blocks. See Why 21 million?.

Who controls Bitcoin?
Nobody on their own. Rules change only if the people running nodes choose to run new software, which is why changes are slow and rare.

Is Bitcoin legal in the UK?
Yes, it is legal to buy, hold and sell. Firms offering crypto services in the UK must be registered with the FCA for anti money laundering rules, but most crypto activity is not covered by the FSCS or the Financial Ombudsman. Check any firm on the FCA Register.

Where do I buy it?
We do not recommend firms. Check a platform on the FCA Register, use app based two factor login, and send a small test withdrawal to your own wallet first. Full steps: How to buy safely in the UK.

Keeping it safe

What is a wallet?
Software or a device that holds your keys, the secret that lets you move your coins. The coins themselves live on the blockchain.

What is a seed phrase?
12 or 24 words that back up every key in a wallet. Whoever has the words has the bitcoin. Write them on paper or metal, never store them digitally, and never type them into a website. See Seed phrases and backups.

Should I leave my bitcoin on an exchange?
On an exchange you hold an IOU, not bitcoin. Exchanges get hacked, freeze withdrawals and go bust. In October 2026 Binance paused withdrawals after a hack (CoinDesk). Many people buy on an exchange and then move savings to their own wallet. See Hold your own keys.

Do I need a hardware wallet?
Not for small amounts. For savings you would hate to lose, a hardware wallet keeps the keys offline so a hacked computer cannot spend them. Buy direct from the maker, never second hand.

What if I lose my phone or hardware wallet?
Your coins are fine as long as you have your seed phrase. Restore it on a new device. If you lose both the device and the seed, the coins are gone for good.

What if I die?
Plan it now. Make sure someone you trust can find your backup and knows how to use it, without giving them access today. Write simple instructions and keep them with your will paperwork.

Someone from "support" messaged me. Is it real?
Almost certainly not. Real support does not message you first and never asks for your seed. Read Avoiding scams and our Passport recall alert.

Sending and fees

How long does a payment take?
A new block arrives about every 10 minutes on average. When it is busy, a higher fee gets you in sooner. Watch the queue on mempool.space.

Why are fees sometimes cheap and sometimes high?
Block space is limited. Fees are priced per unit of data (sat/vB), and when lots of people send at once the price goes up. On 31 October 2026 at 11:15 GMT the fast fee was just 1 sat/vB (mempool.space).

I sent to the wrong address. Can I get it back?
Bitcoin payments cannot be reversed. Only the owner of that address could send it back. Always check the first and last few characters, and send a test first to someone new.

What is Lightning?
A layer on top of Bitcoin for small, near instant payments. Treat Lightning wallets as spending money. See Lightning basics.

For existing holders

Should I run my own node?
A node lets your wallet check the rules itself instead of trusting someone else's server, and keeps your addresses more private. It is optional, but it is the strongest way to verify.

What is a passphrase (the "25th word")?
An extra secret added to your seed that creates a different hidden wallet. It protects against someone finding your seed, but if you forget it the funds are lost. Only use one if you are sure you can back it up.

What is multisig?
A wallet that needs, for example, 2 of 3 keys to spend. It removes single points of failure but adds complexity. Practise a recovery before trusting it with savings.

How do I protect my privacy?
Use a fresh receive address each time, avoid posting your holdings, and be careful with your home address when buying hardware. Data leaks from wallet makers have exposed buyers' addresses, see the Passport recall alert.

Do I pay tax?
In the UK, selling, swapping or spending bitcoin can be a disposal for Capital Gains Tax. The annual exempt amount is £3,000 for 2024 to 2025 onwards (GOV.UK). Keep records of every buy, sell and transfer, and see HMRC guidance. We are not tax advisers.

What is the halving and when is the next one?
Every 210,000 blocks the new coin reward per block halves. The next one is at block 1,050,000. At block 973,969 (31 Oct 2026) that is about 76,000 blocks away, roughly early to mid 2028 at 10 minutes a block (mempool.space). The exact date depends on how fast blocks arrive.

Help

I have been scammed. What now?
Stop sending money. Save screenshots, addresses and transaction IDs and report to Report Fraud. Ignore "recovery" services, they are scams too.

Not financial advice. General education only. Bitcoin's price can swing hard. Never put in more than you can afford to lose, and do your own research.