Finance Matters Insights
UK National Debt Explained: Why it matters for the Budget and your money
The UK is currently in ~£3 trillion of debt and it does impact you.
With the next Budget approaching, the country's debt matters. It significantly influences how much flexibility the Chancellor has, how expensive new policies may be and ultimately, whether the Government chooses to raise taxes, reduce spending or borrow even more.
💷 How does the UK end up owing £3 trillion?
The Government receives money through Income Tax, National Insurance, VAT, Corporation Tax and several other sources.
It then spends money on public services, benefits, pensions, infrastructure and the day-to-day running of the country. When the Government spends more than it receives, it creates a gap known as a deficit. To cover that shortfall, it usually needs to borrow.
That borrowing accumulates over time and contributes to the national debt.
According to the latest figures, UK public sector net debt stood at ~£3 trillion at the end of July 2026. That's equivalent to around 94% of the size of the economy. That doesn't mean the Government has a £3 trillion bill due tomorrow… different portions of the debt need to be repaid at different times, with borrowing stretching decades into the future.
🏦 Who does the Government owe the money to?
When the Government needs to borrow, it can issue something called a Gilt. This is the UK's version of a government bond.
An investor lends the Government money by purchasing the gilt. In return, the Government agrees to pay interest and repay the original amount on a specified date. These gilts are held by pension funds, bank, insurers and others. The Bank of England also owns many.
So, essentially, the Government's debt is someone else's asset. You may actually own part of it indirectly through your pension or investments.
Borrowing isn't automatically bad. It can fund infrastructure, support the economy or cover emergencies. The main question is whether it remains affordable.
If investors lose confidence, or expect higher inflation, it makes debt more expensive as they may demand more interest for new borrowing.
Whilst the debt can be used towards building the economy, the interest itself cannot. In the first four months of this financial year alone, the Government incurred approximately £41billion in debt interest. That's money that cannot be used on public services, household support or tax cuts.
📊 What does this have to do with the Budget?
Before the Budget, the Office for Budget Responsibility (OBR) produces forecasts for the economy and the public finances. It estimates how much the Government is likely to collect in tax, how much it will spend, how quickly the economy may grow and more.
It's the Chancellor's role to work within the limits created by the UK's debt. A large and growing debt means more money is already being spent on interest payments. That leaves less room for tax cuts, extra spending or new support for households… but that money has to come from somewhere.
It means that when the UK's debt position is deteriorating, there is a greater likelihood that we see higher taxes, frozen tax thresholds, reduced planned spending or delays to policies that would be beneficial for the public, but are no longer affordable.
Alternatively, it could choose to borrow more. However, that could then increase future interest costs and make investors less confident in the Government's finances.
In other words, the national debt does not determine every Budget decision, but it does influence it and limits the extent of freedom the Chancellor has.
🗓️ The Autumn Budget
The Autumn Budget is scheduled for 28 October.
It is when our new Chancellor, John Healey, will deliver his first Budget.
Knowing what drives the Chancellor's announcements helps you understand that the decisions are not made in isolation. There are a number of changes and policies that many people would welcome, but the Government may not be able to afford.
Not long to go now, so I'll be back with a full breakdown.
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Fisayo Martins
Founder at Finance Matters UK
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