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Late BAS penalty calculator
See the most the ATO could charge for lodging an activity statement late (the failure to lodge on time penalty) and the interest on paying late, worked out from the ATO’s own rules and rates.
Not sure? Look up your BAS due date.
Starts at today’s date, so a BAS that isn’t lodged yet shows the penalty so far.
Adds an estimate of the general interest charge (GIC) on paying late.
Payment is due on the same date as the BAS. Starts at the lodgment date.
Pick the date the BAS was due to see the penalty.
Nothing you type leaves your browser. An estimate from the ATO’s published rules and rates, not tax advice; the ATO decides any penalty or interest.
How the penalty is worked out
From the ATO’s Failure to lodge on time penalty page (last updated 22 June 2026): the base penalty is one penalty unit for every 28 days (or part thereof) that the document is overdue, up to a maximum of 5 penalty units. It applies to individuals and small withholders, is multiplied by 2 for a medium withholder and by 5 for a large withholder, based on the size of the entity when the document was due.
| When the infringement occurred | Penalty unit | Maximum (5 units, small) |
|---|---|---|
| On or after 1 July 2026 | A$364.00 | A$1,820.00 |
| 7 November 2024 to 30 June 2026 | A$330.00 | A$1,650.00 |
| 1 July 2023 to 6 November 2024 | A$313.00 | A$1,565.00 |
| 1 January 2023 to 30 June 2023 | A$275.00 | A$1,375.00 |
Penalty unit amounts are from the ATO’s Penalty units page (last updated 26 June 2026), which lists older amounts too. You can’t claim a deduction for ATO penalties.
Interest on paying late
The general interest charge applies to tax that remains unpaid after its due date and is worked out daily on a compounding basis. The ATO publishes a new rate each quarter, generally about 2 weeks before the quarter starts (GIC rates, last updated 4 September 2026):
- October – December 2026: 11.51% a year, 0.03153425% a day
- July – September 2026: 11.43% a year, 0.03131507% a day
- April – June 2026: 10.96% a year, 0.0300274% a day
- January – March 2026: 10.65% a year, 0.02917808% a day
The calculator uses each day’s published rate back to July 2023. A late payment notice, a GIC notice or your ATO online services account summary shows what was actually charged, and you can ask the ATO to remit GIC if there are extenuating circumstances.
The simplest way to avoid both is to lodge on time. BAS due dates 2026–27 lists the quarterly, monthly and annual dates (with the online and agent concessions) and gives you a calendar file with a reminder a week before each one.
Common questions
What is the penalty for lodging a BAS late?
The ATO's failure to lodge on time (FTL) penalty is one penalty unit for every 28 days (or part of 28 days) the activity statement is overdue, up to 5 penalty units. A penalty unit is A$364 for infringements on or after 1 July 2026 (A$330 from 7 November 2024 to 30 June 2026). So a small business that lodges 1 to 28 days late could face A$364, rising to a maximum of A$1,820.
Is the penalty bigger for larger businesses?
Yes. The base penalty is multiplied by 2 for a medium withholder and by 5 for a large withholder in the month the statement was due, and by 500 for a significant global entity. The ATO's page sets out the withholding and turnover tests for each.
Will the ATO definitely charge the penalty?
No. The ATO says it generally doesn't apply penalties in isolated cases of late lodgment, considers your circumstances, and warns you by phone or in writing before applying an FTL penalty. This calculator shows the most it could be.
My BAS shows a refund or nothing to pay. Is there still a penalty?
Generally not. The ATO says it won't usually issue an FTL penalty notice for a late activity statement that results in a refund or a nil result, unless the penalty was applied before you lodged, the document is a third-party data report, or you're a large withholder.
What is the general interest charge (GIC)?
Interest the ATO may charge on an amount that stays unpaid after its due date. It compounds daily, and the rate changes each quarter: 11.51% a year (0.03153425% a day) for October to December 2026. GIC incurred on or after 1 July 2025 can't be claimed as a tax deduction.
My agent lodges for me and was late. Am I liable?
Possibly not. The ATO's safe harbour means you aren't liable for the FTL penalty if you gave your registered tax or BAS agent all the information they needed to lodge on time and their failure wasn't reckless or intentional. You'll need evidence that you supplied it.
Can I get a late lodgment penalty cancelled?
You can ask the ATO for a remission, and it can remit all or part of the penalty based on your circumstances. It expects the outstanding statement to be lodged first. Its page lists circumstances it would likely accept (such as severe illness or a disaster) and decline (such as holidays or being busy at work).
How are the days counted?
The ATO counts from the due date to the day before the statement is received, so a BAS due on 28 October and lodged on 29 October is 1 day late (one 28-day period). The amount here uses the penalty unit in force on the day after the due date.
Is this tax advice?
No. It applies the ATO's published penalty rules and GIC rates to the dates and amount you type. The ATO decides whether any penalty or interest applies.
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