ATO Interest and Penalties Overview

An ATO statement of account can be confronting reading: the tax you expected, plus interest lines, plus a penalty you did not see coming. Owners often lump it all together as one punishment. It is not. Interest and penalties are different things, calculated differently, and — importantly — challenged differently. Understanding which is which is the first step to doing something about them.

Interest: GIC and SIC

Interest is the cost of the ATO being out of pocket, not a judgement about behaviour. There are two main charges. The general interest charge, or GIC, applies to amounts paid late. It compounds daily, and the rate is reset quarterly against market rates — it has been in the double digits in recent years, so check the current rate rather than assuming it is trivial. The shortfall interest charge, or SIC, applies when an assessment is amended and extra tax turns out to have been payable all along; it covers the gap between the original due date and the amendment, at a rate set lower than GIC.

One more thing worth knowing: the rules on whether these interest charges are deductible for tax purposes have changed in recent years. Do not rely on the old treatment — confirm the current position with your accountant.

Penalties: a response to behaviour

Penalties are different — they respond to what was done or not done. The most common is the failure to lodge penalty, which is calculated in penalty units for each period a lodgement is overdue, up to a cap. The dollar value of a penalty unit is set by legislation and has been increased several times in recent years, and larger entities face multiples of the base amount — check the current figures rather than budgeting from memory. Penalties for false or misleading statements work differently again: they are calculated as a percentage of the tax shortfall, scaling with culpability from a lack of reasonable care through recklessness to intentional disregard.

Remission is possible — and worth asking about

Both interest and penalties can be remitted, in whole or in part, if the circumstances justify it. A good lodgement and payment history helps. Events genuinely outside your control — serious illness, natural disaster, a system failure — help. What does not help is silence. A remission request is exactly that, a request: it can be declined, and no adviser should promise you an outcome. But we see reasonable requests succeed often enough that not asking is usually the more expensive choice.

Voluntary disclosure changes the mathematics

If you find an error in something already lodged, telling the ATO before it finds the error is treated very differently from being caught. Voluntary disclosure — particularly before you are notified of an audit or review — can reduce shortfall penalties substantially, and it shifts the whole tone of what follows. Waiting to see whether the error surfaces is a gamble in an era when most of your figures are cross-checked against third-party data anyway.

What we commonly see go wrong

• Paying the tax but ignoring the interest, assuming it will be waived automatically. It will not — remission has to be requested.
• Leaving lodgements outstanding because the money is not there. Lodging and paying are separate obligations; not lodging adds penalties on top of a debt that already exists.
• Sitting on a known error, hoping it stays buried, and losing the benefit of voluntary disclosure.
• Accepting a penalty at face value when the circumstances gave real grounds for remission.

A worked example

As an illustration: a business owner discovers that a category of income was left out of an earlier BAS. She asks her agent to lodge a correction and a voluntary disclosure before any ATO contact, together with a short explanation of how the error happened and what has changed to prevent it. The tax and some interest are payable — that was always true — but the penalty outcome is far better than it would have been had the ATO found the discrepancy first through data matching. The facts were identical; the sequence was not.

When to get help

If a statement of account shows interest or penalties you do not understand, if lodgements have fallen behind, or if you have found an error in something already lodged, involve a registered agent before responding. Working out what is remittable, what should be disclosed and in what order is exactly the kind of judgement call that goes better with someone who deals with the ATO every week.

What is the difference between GIC and SIC?

GIC is the general interest charge on amounts paid late, compounding daily at a rate reset each quarter. SIC is the shortfall interest charge applied when an assessment is amended, covering the period before the amendment at a lower rate. Which one applies depends on why the amount was outstanding.

Can ATO penalties and interest be waived?

They can be remitted in whole or in part if circumstances justify it — a good compliance history and events outside your control both help. Remission is a request, not an entitlement, so no outcome can be promised, but reasonable requests are worth making.

I found a mistake in a return I already lodged. Should I say something?

Generally yes, and sooner rather than later. Voluntary disclosure before the ATO contacts you can substantially reduce shortfall penalties, whereas the same error found through data matching is treated less favourably. Speak to your agent about how to frame the disclosure.