Helen Twose: When you're 65 ...

The rules change for KiwiSaver once you reach retirement age. Photo / Getty Images

Q: I am self-employed and will be turning 65 on June 24, 2017. If I put $1100 into KiwiSaver by that date, will I miss out on tax credits for that year?KiwiSaver runs to a different calendar, with the year beginning at the start of July and ending on June 30.

A: Your member tax credit is based on how much you contribute during the KiwiSaver year, not on the calendar year.

It works out at 50c of member tax credit for every dollar you add, up to $1042, and is effectively a tax-free cash top-up from the Government.

You can add more to your KiwiSaver fund each year, but any extra put into your account won't attract additional credits.

It's best to add the full amount to get the maximum credit of $521, but any money added to your KiwiSaver account up to the $1042 counts.

If you're on a salary of $35,000 and making contributions at a rate of 3 per cent, you should contribute enough in the year to get the credit automatically.

People earning less than that may need to make a voluntary top-up to get the full amount.

Those, like you, who are self-employed or not working can also join KiwiSaver and get the member tax credit.

If you have been adding $1100 each year you should have got the full $521.

Turning 65 changes all this.

Once you are 65, as long as you have been a member for five years, you reach your "end payment date" and can withdraw from your funds.

You can still be a member of KiwiSaver and make contributions but you will no longer be eligible for the member tax credit, or the employer contributions if you're in a salaried role - although some employers may continue to pay towards KiwiSaver.

After the end payment date you will be paid a proportion of the credit based on how long you were eligible over the previous year.

In your case, your birthday is about a week from the end of the KiwiSaver year so you could be eligible for roughly $511, provided you contributed $1022.

Similar rules apply to those turning 18 during the KiwiSaver year.

Under-18s don't get the member tax credit or employer contributions until their 18th birthday.

The credit will then be worked out based on the number of days in the KiwiSaver year they were 18.

The same proportionality applies to those joining KiwiSaver during the year.

With the KiwiSaver year ending just over a month ago those member tax credits should be hitting your account about now, if they haven't already.