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Macro EconomyMediumUpdated×2•Originally published 28 October 2026•Updated 28 October 2026•
3 min read

UK Debt Tops £3 Trillion as Fiscal Headroom Shrinks to £15 Billion

Key Facts

1Public sector net debt stood at £3,005.0 billion at the end of September 2026, up £91.7 billion year on year.
2Public sector net borrowing was £24.5 billion in September 2026, £1.9 billion above the Office for Budget Responsibility’s forecast.
3Central government debt interest reached £10.9 billion in September, £2.0 billion above the Office for Budget Responsibility’s forecast.
4Cumulative borrowing was £97.8 billion in the financial year to September, £6.0 billion above the office’s forecast.
5The March update put fiscal headroom at £24 billion, compared with £15 billion in a bond-trader poll in October.

UK public sector net debt stood at £3,005.0 billion at the end of September, up £91.7 billion from a year earlier, according to a provisional estimate published by the Office for National Statistics. The announcement came as Chancellor John Healey put available fiscal headroom at £15 billion, based on forecasts from the Office for Budget Responsibility, according to a Reuters report. The office’s estimate in its March update was £24 billion, while a Reuters poll of bond traders linked the decline to higher borrowing costs and the pressure they put on spending. The figures mean the government enters its budget with less room to meet its fiscal targets, although debt topping £3 trillion did not prevent the debt-to-GDP ratio from falling compared with the previous year, according to the ONS. Healey said the budget aims to help Britain get through "this difficult moment" and put it on a better path for the future.

Public sector net borrowing was £24.5 billion in September, up £1.8 billion, or 7.7%, from the same month a year earlier, and £1.9 billion above the Office for Budget Responsibility’s forecast. By contrast, cumulative borrowing reached £97.8 billion in the financial year to September, down £4.4 billion, or 4.3%, from the corresponding period last year, but remained £6 billion above the office’s forecast. The comparison shows different pictures for September and the financial year to date: monthly borrowing rose year on year, while the cumulative total fell, without matching the forecast. The ONS said borrowing is the difference between total public sector spending and income. These figures put revenue and spending forecasts to the test against the limited headroom announced by the government.

Interest payable on central government debt rose to £10.9 billion in September, up £1.6 billion, or 16.6%, from September last year. The bill was £2 billion above the Office for Budget Responsibility’s forecast and was the highest September figure since monthly records began in 1997, without adjustment for inflation, according to the ONS. The Associated Press estimated that debt servicing requires about 8% of government spending. Interest costs stand out as an item limiting the room available for spending on other priorities, at a time when borrowing costs have risen. Yields on British bonds with maturities of 20 and 30 years reached their highest levels since 1998 in October, while yields on 5- and 10-year bonds hit peaks not seen since 2008, according to Reuters.

The fiscal framework targets a current budget surplus and a decline in public sector net financial liabilities as a share of gross domestic product by the financial year ending in March 2030, according to the ONS. Healey announced on budget day that fiscal headroom stood at £15 billion, down from the March estimate of £24 billion. That makes the path of borrowing and its financing costs relevant to the government’s ability to meet both rules. A Reuters poll of bond traders found the median forecast pointed to a £3.4 billion increase in gross government bond issuance for the 2026/27 financial year, to £249.6 billion after the budget. The budget was scheduled to be presented on 28 October 2026, according to the UK Treasury.