Debt Interest Spending
Of everything on our spending overview, this is the figure with the clearest gap against the primary source. We show £101.4bn; the Office for Budget Responsibility's own current forecast puts 2025-26 debt interest spending at £111.2bn — about £9.8bn higher. Here's the real number and why it matters.
How this actually works
Debt interest is what the government pays to service the national debt — interest to private holders of UK government bonds ('gilts'), and interest on other forms of government borrowing. It moves for reasons largely outside any single government's immediate control: the Bank of England's base rate, gilt yields set by financial markets, and RPI inflation (since a portion of UK debt is index-linked, meaning the amount owed rises directly with inflation). The OBR's own current published figure for 2025-26 is £111.2bn, representing 8.3% of all public spending — up sharply from just 4.6% before the Covid-19 pandemic. This rise is a genuinely significant story in its own right: debt interest is now large enough to be considered the fourth-largest single spending item in the entire UK government budget, behind only social protection, health, and education, and ahead of defence.
Other figures you'll see reported
You'll see different numbers for this in different places. Here's why, so you're not left thinking one of them is simply wrong.
Likely reflects an earlier OBR forecast round or a different net-of-something measure; worth updating to match the OBR's current published figure.
The OBR's own "brief guide to the public finances" states net interest payments are expected to cost £110bn in 2025-26, with the more precise figure in their detailed debt interest forecast at £111.2bn — this is the authoritative number.
The controversy
This isn't a contested political figure the way Welfare or Defence are — it's a straightforward case where our page appears to be using an outdated or differently-scoped number. The OBR revises its debt interest forecast at every fiscal event (roughly twice a year), and forecasts have moved around significantly as interest rate expectations have shifted, so a figure that was accurate at one point can go stale within months. Given debt interest has become large enough to rank as the UK's fourth-biggest spending category — larger than the entire defence budget — getting this one right matters more than most.