Concessional contributions are those payments made before you have paid your personal income tax. They are called concessional due to the fact that the tax is reduced to 15% instead of your normal personal tax rate starting at 19% and going up to 45%.
The government have placed a limit or "CAP" of the amount you may contribute this way. As of 1 July 2017, the cap is $25,000 per year for everyone. If you don't use the full quota available during the year, the unused portion may be able to rollover into up and coming years. Read about it in the ATO article below ...
Keep in mind that your employer's SGC contributions, any salary sacrifice payments and any personal tax deductible contributions are all wrapped up under this category and must not total above the $25,000 cap.
Until 1 July 2017, if you have been receiving a salary, you have not been allowed to make a personal super payment and make a tax deduction from it, however from July 2017, that changes. Many more people will be able to make deductible contributions even though they are receiving a wage.
Read about more of the changes in the ATO Guidance Note --->