I have a 'carry forward of unused concessional contributions' of approximately $35,000. I would like to salary sacrifice this extra $35,000 from my pre-tax salary through my employer in the next financial year. My default super contribution paid by my employer in a year is around $20,000. Therefore, next year, I would like to contribute an additional $35,000 on top of the default $20,000 super contribution.
My question is, can this extra contribution be made from my pre-tax salary, or do I need to make the contribution after-tax and claim a tax refund? Can an employer make a default contribution of $20,000 plus a salary sacrifice of $35,000 in a single year?