ATO says: Super payment due dates occur quarterly. If you don’t pay an employee’s super guarantee (SG) amount in full, on time and to the right fund, you must pay the super guarantee charge (SGC). You must also lodge an SGC statement to us.
The SGC is more than the super you would have otherwise paid to the employee’s fund and is not tax deductible.
When you lodge on time, you can access our support services that provide help with paying. If you can’t pay in full, but you lodge by the due date, you may be able to set-up a payment plan to pay in instalments.
Once you become liable to pay the SGC, nominal interest accrues, nominal interest is part of the SGC and, by law, cannot be reduced or waived.
You will need to complete an SGC statement and submit it to the ATO, this is used to calculate fines and penalties (some to compensate staff for lost earnings, some to punish you for naughtiness). Super must now be paid on all wage types – including overtime, which doesn’t normally attract super.
Hopefully this is a mistake you only make once! Need help to get up to date? Ask us to give you a hand.
ATO source info can be found here: https://www.ato.gov.au/businesses-and-organisations/super-for-employers/missed-and-late-super-guarantee-payments/the-super-guarantee-charge