Money basics
Before the question “which company?” comes a much better one. Move the dials and see the shape of the difference with your own numbers.
I've put an example in to get you going — type your own numbers straight into the boxes, or drag the sliders. Nothing is saved anywhere.
Type it in if it's a big one. Leave it at £0 if you haven’t got one.
Leave it at £0 if you’d rather not.
Illustrative only.
Illustrative only.
Under the mattress
£28,000
Money set aside and never touched. It doesn't shrink — but rising prices quietly shrink what it buys.
In a savings account
£36,996
If the rate were 4% — rates change, check what's on offer.
Invested
£46,059
Based on long-term stock market averages. Real investing goes up AND down — some years it falls. Never a promise.
Over 10 years, the extra £18,059 isn't luck — it's compounding doing the quiet work. But shares only tend to win if you can leave the money alone for years and sit through the falls.
You'd have paid in £28,000 of your own money. Every rate here is an illustration you can change yourself — not a live rate, not a quote, and not a suggestion about any particular bank, account or fund. Real investing goes up and down; some years it falls. — Penny
One cost the dials can't show you: the platform you buy through. What a platform actually costs, side by side — percentage, flat fee and commission-free, in pounds a year.
Penny's honest rule
Before you invest a single pound: build a rainy-day fund first — three to six months of spending, in a savings account you can reach instantly. Investing is for money you won't need for years. If you might need it soon, a savings account isn't boring — it's smart.
One card each, one analogy each. Two minutes, and the jargon stops mattering.
A jar on the shelf. You can always reach it, and it never shrinks.
Money in a bank or building society earning interest. The amount you put in doesn't fall, and up to £120,000 per person per banking licence is protected by the FSCS if the bank fails. The rate can be changed by the bank at any time.
The same jar, inside a lunchbox the taxman isn't allowed to open.
A savings account inside an ISA wrapper, so the interest is tax free. You can pay up to £20,000 a year into ISAs in total, across all of them. Same protection, same steadiness as ordinary savings.
A raffle ticket you get to keep. Most months it wins nothing.
Premium Bonds pay no interest. Every £1 bond goes into a monthly prize draw instead, and your return is whatever you happen to win. The money itself is backed by the Treasury, so the amount you put in doesn't fall — but plenty of people win nothing for months on end, and with a small holding that's the likeliest outcome.
A fruit bowl instead of one apple. If one apple's off, you still have a bowl.
A fund or ETF is a basket of investments in one product — sometimes hundreds of companies. Buying one spreads the risk across all of them, so a single company's bad news matters less. The value still rises and falls, and there's usually an ongoing charge.
One apple. Sometimes lovely, sometimes bruised.
A share is a small piece of one company. If that company does well the share can rise; if it doesn't, it can fall a long way. This is the pot your practice picks come out of.
Seven short reads on the ordinary places money lives in the UK. Start at the top.
The first thing to build, before anything else.
A rainy-day fund is simply money set aside for the week the boiler dies or the hours get cut. Most people aim for three to six months of their usual spending — not their salary, their spending.
It lives in a savings account you can reach the same day. That's the whole job: instant, boring, always there. Money that might be needed within a few years shouldn't be anywhere it can fall.
Once that's sitting quietly in the background, investing becomes a choice rather than a gamble. Until then, it isn't really either — it's just risk you can't afford.
Easy access versus fixed rate, without the sales talk.
An easy-access account lets you take the money out whenever you like. The rate can be changed by the bank at any time, and often is.
A fixed-rate account locks the money away for a set period — a year, two, five — in exchange for a rate that can't be changed while it's locked. Take it out early and you usually lose some interest.
That's the trade, and it's the only decision: do you need to reach this money, or can it sit still? Neither one is clever or stupid. They're for different jobs.
The reassurance nobody bothers to give beginners.
The Financial Services Compensation Scheme — the FSCS — protects up to £120,000 per person, per banking licence, if a UK-authorised bank or building society fails. That limit rose from £85,000 on 1 December 2025. For a joint account it's up to £240,000.
You don't apply for it and you don't pay for it. It's simply there.
One catch worth knowing: several high-street brands can share one banking licence, and the limit applies to the group, not the brand. If you're near the limit it's worth checking which licence each account sits under.
Same wrapper, different filling.
Think of an ISA as a lunchbox the taxman isn't allowed to open. What you put inside is up to you.
Fill it with cash and it behaves like a savings account: interest, tax free, and the number never falls. Fill it with shares and funds and it behaves like investing: it can grow more over long stretches, and it can fall.
The lunchbox is identical either way. You can pay up to £20,000 a year into ISAs in total, across all of them, and you can hold both kinds at once.
What they actually are, odds and all.
Premium Bonds don't pay interest. Instead, every £1 bond is entered into a monthly prize draw, and your "return" is whatever you happen to win.
The money itself is backed by the Treasury, so the amount you put in doesn't fall. But plenty of people win nothing at all for months, and with a small holding that's the likeliest outcome.
So they're best understood as savings with a lottery ticket attached rather than a rate. Some people love that. Others would rather have a boring, predictable number. I'm not going to tell you which you are.
The bit of pay most people quietly leave behind.
A workplace pension is money set aside for much later, and in most jobs your employer pays in alongside you. Some employers will match extra contributions up to a limit.
Where that match exists, it's simply extra money on the table — pay attached to a form nobody ever mentions in the induction.
It's worth ten minutes finding out what your scheme does before you think about anything else. This is general education, not pension advice — your scheme's own paperwork or a qualified adviser is the place for your specifics.
The honest answer is: it depends when you need it.
Money for this year, or the next few: savings account. No debate, no cleverness required.
Money you genuinely won't touch for years, on top of a rainy-day fund: that's when investing starts to make sense, because time is the thing that does the work.
The calculator on this page shows you the shape of it with your own numbers. Have a play with it — nothing you type is saved anywhere.
General education only — no advice, no products named, and no recommendation either way. More of Penny's lessons
