Why do I owe the ATO money, and what the balance is made of

An ATO balance is rarely one debt. Most of it sits on an integrated client account — a running balance account the ATO uses for GST, PAYG withholding and PAYG instalments at once, with general interest charge added daily. Income tax and super guarantee sit on separate accounts, and a credit on one is moved against a debt on another.

What the number on the screen is actually made of

The first useful thing to know is that the ATO does not keep one ledger per business. It keeps accounts, and they are separate. Online services for business lists them apart from one another: an accounts summary, the activity statement accounts, the tax accounts and the super guarantee accounts. Inside the ATO's own systems each one carries a three-digit sequence number — 001, 003, 010 — and the one most businesses mean when they say "my ATO debt" is the account those systems variously call the integrated client account, the activity statement account or the client activity centre. GST, PAYG withholding, PAYG instalments and fuel tax credits all run through it. Income tax does not. The super guarantee charge does not.

The second thing is why that account never matches any letter. It is a running balance account, and the legislation behind it is deliberately loose: the Commissioner may establish one or more systems of accounts for primary tax debts, each is to be known as a Running Balance Account, and they may be established on any basis the Commissioner determines. One account, many obligations, many periods, all netting off against each other. A GST credit for one quarter quietly reduces a PAYG withholding debt from another, and what you are left looking at is a single net position as at today.

The third thing is the part that grows. Where there is a deficit on the account at the end of a day, general interest charge is payable on it for that day — and the balance of the account is then altered in the Commissioner's favour by the amount of that charge. That is what compounding means in law rather than in a brochure: yesterday's interest is part of the principal today. It is currently 11.51% a year for the quarter beginning 1 October 2026, and it is the reason a balance nobody has touched for eighteen months is bigger than the tax that created it.

You are not the first one this week

Most owners who have just worked out what they owe ring their bank next, and most of them are told no. The reasons are almost never about whether the loan would be repaid: the last financials look wrong, a lodgement is late, the credit file has a mark on it, or a tax balance shows up in the statements and the application stops being read. Those are the things a bank exists to care about. None of them says anything about whether there is equity in the building.

That gap is where HomeSec has been since 2004. We are not here to judge how the balance got there, and we have seen it often enough that it does not surprise us. What we look at is whether there is enough unused equity in real property and whether the purpose is a genuine business one — not financials, not a credit score, not whether everything is up to date, and no interrogation about the last two years. From a clean, complete scenario funds can be available in as little as 24 hours, and interest can be capitalised for up to six months so there is nothing payable while the business gets its feet back under it.

Back to the account, because you cannot argue with a figure you cannot explain.

The five things that put the number there

Almost every business balance is some combination of these. Working out which ones apply is what turns a frightening total into a list of decisions.

1. 1
   PAYG instalments set on last year's figures.Both instalment methods are based on information in your most recent tax return, so a good year following a lean one is billed as though it were still lean, and the shortfall lands when the return is lodged. The reverse hurts more: a lean year following a good one is billed at the good year's level all the way through. You can vary an instalment, but only on or before the day it is due and before the year's return goes in — and varying does not change the income tax payable for the year, only its timing. Vary too far and the ATO can charge general interest on the difference: the test is whether the varied instalments come to less than 85% of the total tax payable.
2. 2
   GST reported on invoices nobody has paid yet.On a non-cash basis, GST is accounted for when you issue a tax invoice or receive payment, whichever happens first. Invoice on 60-day terms in the last week of a quarter and the GST is on the activity statement a month before the money exists. A business with aggregated turnover under $10 million can choose the cash basis, which reports GST when the money actually moves. For a business whose customers are slow, that single election is the difference between a BAS it can pay and one it cannot.
3. 3
   GST and PAYG withholding that were never the business's money.This is the uncomfortable one and it is worth saying plainly, because it is the largest single reason businesses carry an ATO balance. The GST was collected from customers and the PAYG was withheld from wages. Both were held on someone else's behalf and both were spent on stock, wages and rent during a month when nothing else was available. Nobody sets out to do it. It happens one quarter at a time, and it is also why unpaid PAYG withholding and GST are the amounts the ATO can make a director personally liable for through a director penalty notice.
4. 4
   An amended assessment after a review or an audit.Where a return is amended and there is a shortfall, the ATO applies shortfall interest charge rather than general interest charge, on the reasoning that a taxpayer is usually unaware of a shortfall until the amended assessment arrives. That is the lower of the two charges — 7.51% against 11.51% for the quarter beginning 1 October 2026 — and it is applied to the period before you knew. It is a smaller mercy than it sounds on an amendment going back two or three years, but it is worth checking which charge has actually been applied.
5. 5
   Interest and penalties on a balance that has simply been sitting.On an older debt this is often a large share of the total, and it is the share that can be reduced. The tax itself cannot be remitted for a company; the general interest charge and the penalties can be, on application and with a reason. What the ATO's own help actually consists of covers how that is asked for, and why nothing in it touches the primary tax.

Why the refund you were expecting did not arrive

A business that lodges a BAS in credit and sees nothing in the bank usually assumes something has gone wrong in the processing. Four things can have happened instead, and only one of them is a delay.

• It was offset. In the ATO's own words, it may apply part or all of a refund against a tax debt you owe — a credit on the activity statement account moving against an income tax debt, for instance. Offsetting generally does not apply to a debt that is due but not yet payable, or to one under a payment arrangement you are complying with, which is a quietly significant reason to keep a payment plan in good order.
• No bank account is nominated. The ATO keeps a refund where it has nowhere to send it. It is the most common cause and the easiest to fix.
• An activity statement is outstanding. A refund is held where one or more statements have not been lodged — one of several reasons that lodging is worth doing even when paying is impossible.
• It is being verified — and there is a clock on that. Where the ATO keeps a refund to check the detail, it must tell you: within 30 days of lodgment for a statement lodged on or after 1 July 2025, or within 14 days for one lodged before then. If it does not notify you inside that window, the refund has to issue.

The same separation of accounts that causes confusion is also useful here. Because the accounts are distinct, a credit can be sitting on one while another runs a deficit and accrues interest — and Online services for business will take a request to transfer a credit balance between accounts, or to refund one where it is more than 50 cents. It is worth ten minutes before borrowing anything.

Reading the account yourself, in about an hour

1. 1
   Open the accounts summary, not the last letter.In Online services for business, the summary shows every account at once — activity statement, income tax, super guarantee. The total you have been carrying in your head is usually one of them rather than all of them.
2. 2
   Open each account and download the statement of account.The transaction list can be filtered by processed or effective date, which matters: the effective date is what the interest was calculated on. Download it rather than reading it on screen, because the next two steps need it side by side with your own records.
3. 3
   Split the balance into tax, interest and penalty.Three different things with three different routes. The tax is owed. The general interest charge and the penalties are discretionary and can be asked about. On a debt that has been running a couple of years the split is often a surprise, and it changes what is worth borrowing.
4. 4
   Reconcile each activity statement period against what was lodged.An estimate the ATO raised because nothing was lodged, a double-counted instalment, or a credit that never found its way across are all visible here and all fixable. If the figure is wrong, this is where it shows.
5. 5
   Check whether a credit is stranded on one account.Then request the transfer. Interest is accruing on the deficit account regardless of what is sitting elsewhere.
6. 6
   Have your tax agent read it with you.An agent sees the same accounts with more history and can ask the ATO things you cannot. This is an hour of their time that routinely pays for itself, and it is the step most people skip because they are embarrassed. Nobody there is surprised either.

What to do with the number once you have it

If the balance is explained, the business behind it works, and the debt is the residue of something that has passed — a slow season, a client who paid late, a project that ran long — then the question is only how it gets cleared. Paying it in full is what stops the general interest charge, ends the exposure to a garnishee notice and removes the risk of disclosure to credit reporting bureaus. Where there is equity in real property and a business purpose, that is what a business loan to pay the ATO does, and the funds go straight to the ATO rather than to the business.

It is the wrong answer in three situations, and we would rather say so here than on the phone. If the interest and penalties are most of the balance, ask for remission before borrowing — a figure the ATO might reduce is not a figure worth financing in full. If the figure itself looks wrong, fix the figure first: borrowing against an estimate raised because nothing was lodged is paying for an error. And if the business is losing money every month and the balance is simply the visible part of that, more debt secured on the family's property keeps a loss running and risks the house as well as the company — the conversation to have is with a registered liquidator about small business restructuring, not with a lender. Where there is no equity in real property, this is not our answer at all: the Small Business Debt Helpline on 1800 413 828 is free, independent and confidential, and a registered liquidator is the other call.

This page explains how an ATO account is built and where a balance comes from. It is general information, not legal, tax or insolvency advice: what to do in your circumstances is a question for a registered tax agent, a registered liquidator or an insolvency lawyer, and the ATO's own published guidance on accounts, PAYG instalments and activity statement refunds is the primary source.

Reviewed by Paul Stone, Joint Chief Executive