What is a bank? — how UK banks actually work | Ages 10–13 guide

Age band: 10–13
Reading time: 6–8 min read
Topic: How banks work
UK relevance: UK-wide
Year: 2026/27
Last reviewed: 2026-05-11

What this guide covers

A bank does three main things: keeps your money safe, lets you pay other people, and lends money out to other customers. Banks pay you a small amount called interest for keeping your money there. They charge a bigger amount of interest when they lend — that's how they make a profit. UK savings are protected up to £85,000 by something called the FSCS.

①The first job: keeping money safe

Before banks existed, if you had money, you had to physically keep it — under a mattress, in a box, in a hole in the garden. That's risky. It can be stolen. It can be lost in a fire. You can forget where you put it.

Banks solved this. You give them your money, they store it digitally, and you can ask for it back whenever you want. Your money still belongs to you — the bank is just holding it.

Important. When you put £100 in the bank, the bank doesn't lock that exact £100 in a safe. It puts a "you have £100" note in a computer, and then uses the actual money for other things (mostly lending it out). When you withdraw, the bank gets the money from its general pool. This works because not everyone withdraws all their money at once.

②The second job: moving money around

You can't hand cash to someone in another city — you'd have to post it or travel there. Banks solve that too. They run a giant invisible system that lets you:

Tap your card and pay someone in a shop
Send money to a friend's account through an app
Set up a regular payment (like Spotify) that comes out automatically
Get paid by an employer who never has to give you physical cash

These all work because nearly every UK bank is plugged into the same payments network. Money moves from your account to theirs through computer messages, usually in seconds (Faster Payments) or by the end of the working day (BACS).

③The third job: lending money

This is the part most people don't think about, but it's how banks actually make money.

Some people put money in the bank and don't need it for years. Other people want to borrow money for big things — a house, a car, a business. Banks connect them: they lend the savers' money to the borrowers, charge the borrowers more interest than they pay the savers, and keep the difference.

Bank pays savers

~3-5% interest

Bank charges borrowers

~5-30% interest

Bank profit

The difference

Mortgage interest (house loans) tends to be lower, around 4-6%. Credit card interest is much higher, often 20-30%. The bank charges higher rates for things that are more likely to not be paid back.

④What is interest?

Interest is a small amount of money the bank pays you for letting them use yours. It's usually expressed as a percentage per year (called the "AER" — Annual Equivalent Rate).

Worked example. You put £100 in a savings account that pays 4% interest per year:

After 1 year: £104 in the account
After 2 years: ~£108.16 (because year 2 earns interest on the £104, not just the £100)
After 10 years: ~£148

The reason year 2 is more than year 1 + £4 is something called compound interest. You earn interest on your interest. It's small over 1 year but huge over 20 years. This is the most important idea in saving.

Quick maths. Doubling time formula: divide 72 by the interest rate. At 4%, money doubles in 72÷4 = 18 years. At 8%, in 9 years. Useful when you're trying to picture how long savings will take to grow.

⑤The FSCS — what protects your money

The Financial Services Compensation Scheme (FSCS) is a UK government-backed safety net. If a bank goes bust, the FSCS pays you back up to £85,000 per person, per bank.

This is why nobody needs to worry about losing money in a normal current account or savings account. Even if the bank itself fails (rare but it has happened — Northern Rock in 2008 is the famous example), your money is safe up to the limit.

What's covered:

Current accounts and savings accounts at any UK-regulated bank or building society
Cash ISAs and Cash JISAs
NS&I products (covered separately by HM Treasury, 100% protected)

What's not (or only partly) covered:

Stocks and shares investments (different protection up to £85k, but the value of investments can go down regardless)
Cryptocurrency (zero FSCS protection)
Money sent to scammers (the FSCS isn't designed to cover fraud loss)

If you have a lot. Above £85k in one bank, you spread money across multiple banks to stay protected. Most teenagers won't hit this for years.

NCNational Curriculum links

England — PSHE Association KS3 L24 (managing money), L25 (financial decisions)
England — Citizenship KS3 (operation of the economy)
England — Maths KS3 (percentages, financial mathematics)
Wales — Curriculum for Wales Progression Step 3-4 (HWB AoLE)
Scotland — Curriculum for Excellence MNU 3-09a (financial education)
NI — LLW KS3 Personal Finance basics

Full mapping in the curriculum map.

Cite this guide
UK Tax Drag (2026). What is a bank? — how UK banks actually work. Ages 10–13 guide. Available at: https://kids.uktaxdrag.co.uk/ages-10-13-what-is-a-bank.html
Curriculum mapping: see UK Financial Education Curriculum Map (Version 1.0).

Not financial advice. This guide explains how the UK system works for learning. If you're under 18, ask a parent or carer before doing anything with real money. UK rates and rules can change — always check gov.uk for the latest.