On 2 August 2025, the Australian Government received Royal Assent for changes in the way the Study and Training Support Loan Compulsory Repayments are calculated. These include:
an increase to the threshold
a change in the repayment calculation to a marginal system
For more information on the changes, refer to Study and training loans – what's new | Australian Taxation Office.
The ATO has updated Schedule 8 - Statement of formulas for calculating study and training support loans components (NAT3536) and the relevant tax tables. See the links below:
Whilst the new formula is effective from 1 July 2025, Employers need to apply the updated formula to withholding tax from payments made on or after 24 September 2025. Any potential overpayments of STSL, from between 1 July and 24 September, will be corrected when the employee completes their Tax Return.
The change in the formula used to calculate STSL tax rates requires a Coefficient B value, which is not used in the current formula. To prepare for the changes in formula, you need to upgrade to version 9.4 SP2, see September 2025 - Access MicrOpay Evo 9.4 SP2.
Note: The 9.4 SP2 upgrade includes changes to the layout only and does not include updates to the STSL Tax rates.
Tax changes are usually applied as part of End of Year Processing after all pays for the year are complete. Applying a mid-year tax change is an unusual event. Providing a separate update allows you to manage when the updated STSL tax rates are applied, to fit in with your payroll process.
To apply the updated STSL Tax changes
There are two options to update your STSL tax tables:
Upgrade to MicrOpay Evo version 9.4 SP2 B1
Payroll Hosted Online customer - upgraded Friday 19 September 2025 8:00 pm - Saturday 20 September 2025 8:00 pm AEST.
On-Premise Desktop customer - the release will be available to download Monday 22 September.
Download and run the STSLChanges24Sep2025 script below. You must be on MicrOpay Evo version 9.4 SP2 before you run the script. For instructions on running scripts, see Run a script.