Britain’s budget deficit is the gap between what the public sector receives and what it spends over a given period. When spending exceeds revenue, the government borrows to cover the difference. That borrowing adds to public-sector debt, but the deficit and the debt are not the same thing.

Why governments run deficits
Borrowing can rise during recessions, emergencies or periods of major investment. Tax receipts may fall while spending on benefits and public services increases. A deficit is therefore not automatically evidence of poor management; its significance depends on why borrowing is rising, how long it persists and what the money is financing.
The main choices are political
A government seeking to reduce borrowing can raise revenue, restrain spending or rely on stronger economic growth to improve the fiscal position. Each option creates different distributional effects. Tax rises fall differently across households and firms, while spending restraint affects services, investment and welfare provision.
Borrowing for day-to-day spending is also politically different from borrowing for infrastructure that may increase future productive capacity. Fiscal rules try to impose discipline on those choices, but the design of the rules is itself a political decision.
Interest costs matter
Higher debt does not create the same pressure in every economic environment. The cost depends on interest rates, inflation, growth and the maturity structure of government borrowing. When debt-interest costs rise, they compete directly with other priorities in the budget.
Why the OBR matters
The Office for Budget Responsibility produces independent forecasts for borrowing, debt and the wider economy. Its role is not to decide fiscal policy, but to test whether government plans are consistent with the assumptions and rules ministers have set.
For voters, the useful question is therefore not simply whether the deficit is large or small. It is what is driving it, whether borrowing is temporary or structural, and what trade-offs the government is making to change its path.
Explore the Office for Budget Responsibility’s forecasts and fiscal analysis.