Pensioners have been urged to see a financial consultant after many recipients were slugged with extra tax this week.

Recipients of Commonwealth and Defence pensions reported a spike in tax taken from their fortnightly payments.

This was despite an increase of 0.1 per in the CPI-based increase, equating to about $1 extra a fortnight.

But Dixon Advisory executive chairman Daryl Dixon urged low-income earners to speak to an accountant for advice on changes to the tax system introduced this financial year.

Tax changes that came into effect on July 1 include an increase in the personal tax rate from 15 per cent to 19 per cent where the tax-free threshold has not been claimed.

Mr Dixon said: ''If you're on a relatively low income and your tax has risen then you need to check whether you claim the tax-free threshold.

''If you're not claiming the tax-free threshold, then you're paying more tax.

''You can check that with your accountant. Tax time is here so it's easy to check when doing this tax return.''

Mr Dixon said only higher income earners should have experienced a tax increase, after the tax-free threshold increased from $6000 to $18,200.

''People don't pay tax until they get above $20,000.

''This year, more than ever before, it's very important you are claiming the tax-free area if you're eligible for it.

''You can only claim the tax-free threshold once, so those with two sources of income need to choose.

''If you're uncertain and on a low income, you should check with your accountant.''