BUDGET ANSWERS · THE PUBLIC FINANCES
How much does the UK spend on debt interest?
Short answer: About £109.4bn in the first year of the game, around 8p in every pound the government spends. With no changes, it is £137.1bn a year by the election.
The bill you inherit
The game starts from OBR March 2026 totals: £1,304bn coming in and £1,419.5bn going out, a gap of £115.5bn that has to be borrowed. Debt stands at about 95% of the economy.
Interest is paid before a single nurse, teacher or soldier. Every pound borrowed adds to the debt, and the interest on it keeps coming. If markets lose confidence, the rate on new borrowing rises and the bill grows faster.
Why it matters in the game
Tax cuts and spending rises paid for by borrowing do not stay the same size: debt interest builds up on top. That is why a policy that costs £8bn in its first year can add more than that to borrowing five years later. See the individual answers below.
These figures come from the game’s simplified model, not an official forecast. Read the model register.