What the chart shows
1993 to 2007: steady. Debt rose in cash terms but stayed between roughly 29% and 37% of GDP. It fell in 2000, by £35bn, when the government ran a budget surplus and paid some of it down.
2008 to 2019: the financial crisis and after. Debt went from £574.7bn at the end of 2007 to £1,152.5bn at the end of 2010, the first year it ended above £1 trillion. As a share of the economy it rose from 36.1% to 84.2% by 2019, and never returned to pre-crisis levels.
2020 onwards: Covid and the cost of borrowing. Debt jumped by £317bn in 2020, the largest rise in the series, ending the year above £2 trillion for the first time at 97.7% of GDP. It has stayed between 93% and 97% of GDP since, while still rising by more than £100bn every year in cash terms. The live counter estimates where it stands today, and our £3 trillion page tracks the next milestone.
Why the % of GDP view matters
Cash figures always look alarming over long periods because prices and incomes rise too. Dividing the debt by the size of the economy (GDP) shows how heavy it is to carry. Switch the chart to % of GDP and the story changes shape: flat for fifteen years, then two big steps up, in 2008–10 and in 2020, and a plateau since.
Where the figures come from
Every figure is the Office for National Statistics' measure of public sector net debt excluding public sector banks, the headline measure of UK national debt, taken at the end of December each year. The ONS revises past figures as better data arrives, so they can differ slightly from what was reported at the time: the end of 2020, for example, was first published as £2,131.7bn and is now £2,154.2bn.