Budget deficit.
In plain English
A budget deficit is what happens in a year when the government's spending exceeds the revenue it takes in, mostly from taxes. It covers the gap by borrowing, which adds to the national debt. The reverse, collecting more than it spends, is a surplus. Deficits tend to widen in recessions, when tax revenue falls and support spending rises, and narrow in strong economies. The deficit is a one-year flow; the debt is the running total those yearly flows build up to.
01Why it matters
The deficit shows whether the government is adding to its debt and by how much this year, so separating this annual flow from the total debt is key to reading budget and election-season claims accurately.
02The math, step by step
If the government collects a certain amount in a year and spends more than that, the difference is the deficit for that year, and it gets borrowed. Run a deficit every year and the debt keeps climbing; run a surplus and the debt can actually fall.
03What this is NOT
It is not the total debt. A deficit is one year's shortfall. The national debt is every past deficit added up minus any surpluses. You can cut the deficit and still add to the debt, as long as the deficit is above zero.
04Receipts
Every figure on this page is sourced to a primary document. Tap to open the original.