What is inflation — and what does it actually mean for your budget?

You've probably noticed that things cost more than they did a few years ago. Your weekly shop, your energy bills, eating out, a pint — the numbers keep going up. That's inflation. Not a conspiracy, not a malfunction — just how money and prices work over time.

But what actually causes it? Why does it sometimes spike dramatically? And what does it mean for how you manage your money day to day?

What inflation actually is

Inflation is the rate at which prices across an economy rise over time. When inflation is at 3%, something that cost £100 last year costs roughly £103 this year. At 10%, that same thing costs £110.

It's measured using what's called a "basket" of goods and services — a representative sample of things households typically buy. Statisticians track how the price of that basket changes over time, and that change is the inflation rate. In the UK this is the CPI (Consumer Prices Index), in the US it's also called CPI, in the Eurozone and Australia similar measures are used.

A small amount of inflation — around 2% — is considered normal and healthy by most central banks. It encourages spending and investment (because money sitting idle loses value slightly). The problem comes when inflation spikes much higher than that.

Why do prices go up?

There's rarely one single cause. Inflation typically comes from a combination of forces:

Too much money chasing too few goods

When governments pump money into an economy — through stimulus payments, low interest rates, or borrowing — people have more to spend. If the supply of goods and services doesn't grow to match, sellers can charge more. More money, same amount of stuff: prices rise.

Supply chain disruption

When the supply of something is reduced or disrupted — a factory shuts down, a shipping route is blocked, a harvest fails — the same demand now chases less supply. Prices go up. The COVID-19 pandemic caused significant inflation partly for this reason: factories closed, shipping containers ended up in the wrong places, and supply chains that rely on just-in-time delivery fell apart.

Energy prices

Energy costs feed into almost everything — manufacturing, transport, heating, growing food. When energy prices spike (as they did globally in 2021–2023 following the war in Ukraine), costs rise across the whole economy. Businesses pass those costs on to customers.

Wages rising faster than productivity

If wages rise faster than the economy's output, businesses face higher costs and typically raise prices. This can create a feedback loop — higher prices lead workers to demand higher wages, which leads to higher prices again.

What does inflation do to your money?

The core effect is simple: your money buys less over time.

£1,000 sitting in a current account paying no interest will buy less in two years than it does today. If inflation is running at 4% and your savings earn 1%, you're losing purchasing power at 3% per year. The number in your account stays the same, but what it can actually buy shrinks.

This is why "keeping it under the mattress" is always bad advice. Cash that earns nothing is slowly losing value. Even modest interest — from a regular savings account — partially offsets this erosion.

For people on fixed incomes (a fixed pension, for example), inflation is especially damaging because their income doesn't rise to match rising costs. For people with variable-rate loans or mortgages, high inflation often pushes up their interest costs too, as central banks raise interest rates to try to cool inflation down.

How central banks respond

When inflation is running too high, central banks — like the Bank of England, the US Federal Reserve, or the European Central Bank — typically raise interest rates. Higher interest rates make borrowing more expensive, which slows spending and investment. Less spending means less upward pressure on prices. Eventually inflation falls.

The downside is that higher interest rates also make mortgages more expensive, increase the cost of any variable-rate debt, and can slow economic growth. It's a blunt tool.

When inflation is too low (or when there's a risk of deflation — falling prices), central banks do the reverse: cut rates and inject money into the economy to encourage spending.

How to budget through high inflation

When prices are rising faster than your income, the gap between what you earn and what you need to spend narrows. Here's how to manage that practically:

1. Know where every pound is going

When costs are rising, a rough idea of your budget is no longer enough. You need to know exactly what your essential costs are so you can identify where the pressure is building and where there might be room to adapt. A clear monthly budget is the starting point.

2. Review subscriptions and fixed costs

Subscription creep — small monthly charges that accumulate without you noticing — is always worth a periodic audit. A few cancellations can meaningfully offset the impact of rising food or energy costs.

3. Don't let savings sit completely idle

If your emergency fund or savings are sitting in an account earning nothing while inflation is running at 4%, they're quietly shrinking in real terms. Moving savings to an easy-access account at a reputable bank or building society that pays a competitive interest rate is a simple step. You don't need to take any risk — just make sure your money is earning something rather than nothing.

4. Prioritise paying down variable-rate debt

When interest rates rise in response to inflation, variable-rate loans, credit cards, and tracker mortgages all get more expensive. If you have high-interest debt, reducing it becomes even more important during inflationary periods.

5. Adjust your budget regularly

A budget you set 18 months ago may no longer reflect your actual costs. During periods of elevated inflation, it's worth reviewing your fixed and variable expenses every few months and updating your figures. Your grocery budget from two years ago is almost certainly no longer accurate.

The bottom line

Inflation is a normal part of how economies work — the problem is when it gets out of control, and the years since 2021 have been unusual by recent standards. The good news is that you don't need to understand the economics in detail to protect yourself from it.

The practical response is the same as good budgeting always is: know what you're spending, cut what you don't need, keep debt under control, and make sure any savings are actually earning something rather than sitting still while prices move around them.