Contributions made by an employer (including contributions made under a salary sacrifice arrangement) and personal contributions claimed as a tax deduction by a self-employed person are considered to be Concessional contributions.
Concessional contributions are taxed at 15% in the hands of the superannuation fund. A limit of $25,000 applies to concessional contributions. However, a transitional period applies until 1 July 2012 in which people 50 years of age and over can make contributions of up to $50,000 per year per person without breaching the limit. A person turning 50 years of age during this transitional period can take advantage of these arrangements from the time they turn 50 years of age.
The limits apply per person regardless of the number of employers making contributions on your behalf. If your concessional contributions exceed $25,000 in a financial year, you will be notified by the Australian Taxation Office (ATO). The excess contributions will effectively be taxed at the top marginal rate plus the Medicare levy (currently 46.5%). You can ask your super fund to release money to pay this excess contributions tax from your super account.