Government debt: how Australia borrows, and the limit that can move

Government debt isn't printed money. When the Australian Government spends more than it raises in tax, it covers the gap by borrowing — and it borrows by issuing securities called Australian Government Securities, or AGS. Investors buy them; the government promises to pay the money back, with interest, on a set date.

There are three main kinds. Treasury Bonds pay a fixed rate of interest — a "coupon" — twice a year and repay their face value at maturity; most government debt is in these. Treasury Indexed Bonds work the same way, but their value rises with inflation, so the lender is protected against rising prices. Treasury Notes are short-term, repaid within about a year, used to smooth out the timing of money coming in and going out.

Add it all up and that's the debt: a stack of promises to repay, not a pile of printed cash.

The government doesn't ring around for loans itself. A specialist agency, the Australian Office of Financial Management (AOFM), does all the borrowing on its behalf. The AOFM sells AGS at regular auctions, where banks and dealers bid to buy them.

Who ends up holding the debt? A mix — Australian super funds, banks and insurers, the Reserve Bank, and a large share of overseas investors. They lend because government bonds are about the safest place to park money and earn a steady, predictable return.

In return, the government pays interest along the way and repays the face value when each security matures. That interest — the cost of servicing the debt — is the part that grows as debt grows, and it's money that then can't be spent on anything else.

You'll often hear that government debt has a "$1.2 trillion limit". That's real — but it isn't the hard wall the word suggests. Australia did once have a legislated debt ceiling, like the United States: Parliament set a dollar cap, starting at $75 billion in 2008 and lifted step by step to $300 billion. In December 2013, rather than raise it again, Parliament abolished it altogether.

What replaced it is softer. Under the Commonwealth Inscribed Stock Act 1911, the Treasurer sets the maximum value of government securities that can be on issue by issuing a direction — currently $1.2 trillion. Because the Treasurer sets it, rather than Parliament legislating a fixed ceiling, it can be revised: it's a guardrail the government adjusts, not a wall that has to be voted up.

And it's expected to be adjusted. The 2026-27 Budget projects gross debt reaching $1.1 trillion during 2027-28 and passing the $1.2 trillion limit during 2029-30 — so the limit will be lifted before debt gets there. (The cap covers the face value of government securities on issue, a few minor categories aside.)

This is why Australia doesn't have the debt-ceiling dramas the United States does. There, hitting the ceiling can trigger a real crisis — the risk of default, government shutdowns, market turmoil — because raising it needs a fraught vote. Here, the limit is lifted quietly as needed, so it rarely makes the news.

Debt gets quoted in a few different ways, and they aren't the same number. Gross debt is the face value of all government securities on issue — the headline figure, heading towards $1 trillion through 2026. Net debt subtracts the financial assets the government holds (cash, investments, loans it's owed), so it's smaller; the 2026-27 Budget puts it around $616 billion.

The third way scales debt against the size of the economy: debt-to-GDP. It's the most useful for comparing over time or between countries, because a dollar figure alone doesn't tell you whether debt is large relative to what the country produces. On that measure, Commonwealth gross debt is projected to peak around 35.8% of GDP in 2028-29.

One trap worth knowing: the debt figure on Capibrain's dashboard from the IMF (around 50% of GDP) is a broader measure than the Budget's — it counts all levels of government, not just the Commonwealth. Same idea, different scope; they aren't meant to match.