Basics

A beginner's guide to cryptocurrency: how it works, buying it and keeping it safe

CryptoSurge HQ · Updated 18 October 2026 · How we write

Cryptocurrency is digital money that is not issued by a central bank. Instead of a bank keeping the record of who owns what, the record is a shared ledger called a blockchain, copied across thousands of computers. This guide explains how that works, how people buy and store crypto, and what can go wrong.

What a blockchain actually is

A blockchain is a list of transactions grouped into blocks. Each block contains a reference to the one before it, so the blocks form a chain. Changing an old transaction would mean rewriting every block after it, and the rest of the network would reject the altered copy. That is what makes the record hard to tamper with.

Bitcoin, launched in 2009, was the first widely used cryptocurrency. Its design was set out in a short white paper published under the name Satoshi Nakamoto. Since then thousands of other coins and tokens have appeared. Some run on their own blockchains, such as Ethereum; others are tokens issued on top of an existing chain.

How new transactions get agreed

A network needs a way to agree which transactions are valid. The two main methods are:

Proof of work, used by Bitcoin. Computers called miners compete to solve a puzzle, and the winner adds the next block and earns newly created coins plus fees. It uses a lot of electricity by design.
Proof of stake, used by Ethereum since 2022. Validators lock up coins as a deposit and are chosen to propose and check blocks. If they cheat, part of the deposit can be taken away.

Wallets and keys

You do not hold crypto in the way you hold a banknote. What you hold is a private key: a long secret number that lets you move coins recorded on the blockchain. A wallet is software or a device that stores that key and signs transactions for you.

Most wallets give you a recovery phrase, usually 12 or 24 words, when you set them up. Anyone with those words can take everything in the wallet, and if you lose them and the device, the funds are usually gone for good. No bank or helpline can reset it.

There are two broad ways to hold crypto:

On an exchange (custodial). The platform holds the keys and you log in with a password. It is convenient, but you rely on the firm staying solvent and honest.
In your own wallet (self-custody). You hold the keys. Nobody can freeze your account, but every mistake is yours to live with. Our self-custody guide covers this in detail.

How people buy crypto in the UK

Most people buy through a crypto exchange or a trading app. Before using any firm, check it on the FCA's Financial Services Register. Crypto firms serving UK customers must be registered with the FCA for anti-money-laundering purposes, and firms promoting crypto to UK consumers have to follow the FCA's rules on financial promotions, including clear risk warnings.

Registration does not mean the FCA protects your money. If a crypto firm fails or you are scammed, you are unlikely to be covered by the Financial Services Compensation Scheme or able to complain to the Financial Ombudsman Service.

When you buy, look at the full cost: the spread between buying and selling prices, trading fees, and any charge to withdraw coins or pounds. These can add up, particularly on small, frequent purchases.

The main risks

Price swings. Crypto prices can fall sharply in a short time, and some coins have lost almost all their value.
Platform failure. Several large crypto firms have collapsed, leaving customers waiting years for part of their money, or getting nothing.
Scams. Fake investment schemes, impersonation and phishing are common. See our guide to the warning signs of crypto scams.
Mistakes. Sending coins to the wrong address or the wrong network usually cannot be reversed.
Tax. Selling, swapping or spending crypto can create a tax bill. Our UK rules and tax guide explains the basics.

Questions to ask yourself first

Could I afford to lose all of this money without it affecting my bills, savings or debts?
Do I understand what this coin or token is for, and who is behind it?
Have I checked the platform on the FCA register?
Do I know how I will store it, and where my recovery phrase will be kept?
Am I being rushed, or has someone I met online suggested it? If so, stop.

If any of these give you pause, it is fine to wait. Learning how the technology works costs nothing, and you can read more on the official sites listed below.

Sources and further reading

Not financial advice. This article is for general information and education only. It is not financial advice or a recommendation to buy, sell or hold any cryptoasset. Cryptoassets are high risk and largely unregulated in the UK: you could lose all the money you put in, and you are unlikely to be protected by the Financial Ombudsman Service or the FSCS.