Can I do that? Thanks to recent changes, this year the co-contribution will be available to a wider range of investors. For the first time since its introduction it has been indexed in line with average weekly earnings. This means you'll be eligible for the full co-contribution of up to $1500 if your assessable income including reportable fringe benefits is less than $28,980, and a partial co-contribution if your income is less than $58,980. But the big change is that eligibility has been extended to the self-employed, provided their income is under the same thresholds. The co-contribution formerly was available only to employees.

How does it work? To be eligible you must be under 71, meet the residency requirements and earn at least 10 per cent of your total income from carrying on a business or employment (the 10 per cent test). For employees, the income thresholds apply to your assessable income plus reportable fringe benefits - that is, your income before deductions are allowed. So if your taxable income is reduced by negative gearing, for example, those deductions won't be taken into account in determining your income for co-contribution purposes.

For the self-employed, it gets a bit more complicated. In determining whether you meet the 10 per cent test, your assessable income and reportable fringe benefits is used - without allowing for deductions for business expenses.

But once you've met that test, your business expenses can be taken off your income when determining how much co-contribution you get.

Westpac Financial Planning's technical team used the example of Keith to show how this works. Keith has business income of $20,000, employment income of $20,000 and income from a rental property of $10,000. He is claiming tax deductions for $15,000 in business expenses and $8000 in rental property expenses.

When determining whether Keith meets the 10 per cent test, his full $50,000 income is taken into account without allowing for any of his expenses. As he earns $40,000 (or 80 per cent) of his income from employment and carrying on a business, he meets that test easily.

But in calculating Keith's maximum co-contribution, his business expenses (but not his rental expenses) can be deducted from his income - giving him an income of $35,000. Westpac says this would give him a maximum co-contribution of $1199.

So how do I get the co-contribution? You need to make a personal contribution to a complying super fund or retirement savings account from your after-tax income before June 30. Tax deductible contributions, or contributions made on your behalf by your spouse, don't count.

The Government will then contribute $1.50 for each $1 you put in, up to a maximum co-contribution of $1500 if you're under the minimum income threshold. That is, if you put in $1000, it will contribute $1500.

If your income is above $28,980 your maximum co-contribution is reduced by five cents for each extra dollar earned. So if your income is $45,000, your maximum co-contribution is $699; if your income is $55,000, it's $199. (There's a handy calculator at http://www.ato.gov.au if you don't want to do the sums yourself.) To get the maximum co-contribution someone earning $45,000 would need to contribute at least $466, while you'd need to contribute at least $133 to get the maximum if your income was $55,000.

Note that your total level of personal contributions is taken into account, so it doesn't matter whether you make a one-off contribution or spread your contributions over the year.

Didn't I read that the co-contribution had been increased? In its last budget, the Coalition Government doubled the co-contribution. But this was a one-off extra payment to people who had already become entitled to a co-contribution for the 2005-06 year. Labor has indicated it would like to extend the co-contribution but that's unlikely to happen any time soon.

How do I claim the co-contribution? You don't have to. The Tax Office will pay it automatically using information from your tax return and your super fund. It will be paid automatically into the same fund you contributed to unless you nominate another fund.