That's not much time, and many people are likely to be unaware of the changes, says Michael Hutton, the head of wealth management at HLB Mann Judd Sydney.

The last time there was a change of this magnitude to the super rules, there was at least a year's notice, he says.

Those changes by Peter Costello in 2006 and 2007 were also dubbed the $1 million opportunity, as up to that much could be tipped into super as part of the wide-ranging rule changes.

Before the latest changes kick in on July 1, a couple can put up to $540,000 each into super or up to $1.08 million in total under the bring-forward rule. That's why it's being called the $1 million opportunity.

The new rules were only passed by parliament in late November last year. And there has been the holiday period from which many people have only recently returned to work.

Non-concessional caps

From July 1 this year, the "non-concessional" cap will reduce to $100,000 each financial year from $180,000.

A non-concessional contribution is money from savings, inheritance, redundancy payout, or the sale of shares or property, for example.

That's different to "concessional" contributions, such as salary sacrifice into super, where the marginal rate of income tax is swapped for the 15 per cent super contributions tax that applies to most people.

The concessional cap is also coming down from $35,000 for over-50s and $30,000 for under-50s to $25,000 for everyone from July 1. The $25,000 includes the 9.5 per cent compulsory super paid by employers.

From July 1, the three-year bring forward will be $300,000 to reflect the lower annual cap.

New $1.6 million cap

Phillip Gillard, a financial planner at Shadforth Financial Group, says there is a further incentive to act before July 1 for those with large superannuation account balances.

That's because, from July 1, non-concessional contributions will not be allowed by those whose super balances are higher than $1.6 million.

From July 1, a maximum of $1.6 million will be allowed to be held by a retiree in a pension where no tax is paid on the money.

However, non-concessional contributions before July 1 that push the balance beyond $1.6 million will be able to stay in super, Gillard says.

Those who will have more than $1.6 million in a pension will be required, from July 1, to either take the excess out of super, or to put it into an accumulation super account where the 15 per cent tax applies on earnings, he says.

Melinda Houghton, a financial adviser and founder of Houghton Strategic Solutions, says not that many people are able to make really big non-concessional contributions.

"But someone could be thinking of selling something and I would be thinking of bringing the sale forward to before June 30 to take advantage of the higher non-concessional caps," she says.

"However, all aspects have to considered before bringing forward a sale, including any tax events such as tax on capital gains from the sale of shares or property," Houghton says.

Concessional caps

Gillard suspects many people may think that they have to do something before July 1.

"But the reality is that for most people the $100,000 non-concessional cap per person will be enough," he says.

More people are likely to be affected by the new $25,000 cap on concessional contributions, he says.

Another of the government's super changes is that the unused concessional cap can be carried forward for up to five years.

That means that up to $125,000, less compulsory super, can be put into super over a five-year period as long as the super balance is less than $500,000.

This measure was to start on July 1 this year, but it has been deferred until July 1, 2018.

Houghton says it is those in their 50s, especially women, who have increased their hours of paid work, who are the most likely to take advantage of the catch-up measures.

As well as increasing their hours of paid work, their children have finished school and the mortgage, if not paid off, is likely to be much smaller, she says.

Hutton points to the opportunity to use the higher concessional caps that are available for the remainder of this financial year.

Personal contributions

Dennis Eagles, the national head of self-managed superannuation at Grant Thornton Australia, says another important change is that which extends the tax benefits of sacrificing salary into super to almost everyone.

From July 1 this year, those under the age of 65, and those aged 65 to 74 who meet the work test, will be able claim a tax deduction for personal contributions to super, up to the $25,000 concessional contributions cap.

It's important to keep in mind this cap is inclusive of compulsory super contributions, Eagles says.

Small employers sometimes do not offer salary sacrificing to their employees and these employees will now be able to make personal contributions.

It will also benefit those who are partially self-employed and partially wage earners, such as self-employed contractors. They will be able to make contributions and receive the same tax benefits as if they were salary sacrificing through an employer.

Robert Ross, a senior financial adviser with Fitzpatricks Private Wealth in Sydney, points to another benefit of this change.

It means that people can make personal contributions to their super from proceeds of, say, a sale of shares, where tax is payable on the capital gains.

That can reduce the amount of taxable income and, therefore, reduce the tax paid on the capital gains.

This extension of the ability to make personal contributions is even more powerful after July 1, 2018, when $125,000 of deductible contributions, less compulsory super, can be put into super over a five-year period as long as the super balance is less than $500,000.

That means even larger proceeds from an investment on which capital gains tax is payable can be put into super as a personal contribution and get the tax deduction.

If the money is an inheritance, for example, on which no tax is payable, it would usually be better to put that into super as a non-concessional contribution, Ross says.

That's because the 15 per cent super contributions tax that applies to most wage earners does not apply to non- concessional contributions, he says.