Three-quarters of employers could face a 10 per cent increase in payroll costs as a result of the changes to the superannuation legislation, according to a Mercer survey.
Employees also face the possibility of reduced cash bonuses.
From July 2008, the definition of ordinary time earnings will be widened to include items such as performance bonuses, commissions and shift loadings.
Employers will now have to take these items into account as the earnings base when calculating the 9 per cent superannuation guarantee SG levy.
The survey showed 15 per cent of employers were unaware of the changes and more than a third were yet to understand the cost impact on their company as a result of the new legislation.
Mercer noted that as employers would need to contribute to an employee's superannuation fund 9 per cent of any bonus or commission paid, they would now have to decide whether they would bear the additional superannuation contributions.
The other option for employers is deducting the additional superannuation contributions from any bonus or commission paid, reducing the employee's cash payment.
"This may not be possible without negotiating contracts and employment agreements, hence they need to act now and communicate the changes to employees prior to implementation," Mercer chief executive Peter Promnitz said.
