Employees are permitted to contribute to their superannuation using salary sacrifice, this is where you ask your employer to pay your superannuation company without paying it to you.
By sacrificing some of the amounts as a contribution to the super fund, you are reducing the amount of tax to 15%. The advantage is that your take-home pay is reduced and you will pay less tax.
If your employer has no limit on the amount that you can salary sacrifice there are no limits on the amount you can do salary sacrifice.
If you decide to enter an agreement with your employer to salary sacrifice then you need to consider that the amount you contribute plus the amount the employee contributes should not exceed the concession contribution cap.
For example, if you are aged 55 years and your superannuation balance is more than $500,000 and your employer contributes $20,000 to your superannuation then your salary sacrifice should not exceed $5000, any excess amount is taxed up to 47%.
Your salary sacrifice may attract Division 293 tax if you have an income and concession contribution of more than $300,000.