If someone suggested you pay a few hundred dollars a year more than you have to, to your power company, on the understanding that you will get a refund at the end of the year, you would probably think they were mad.
But a lot of people still operate this way with their tax bills.
They pay more than they have to throughout the year - in some cases, significantly more - and wait for the end of the tax year to get the difference back.
We are at that time of year now - have you discovered you are one of them?
Paying more than you need to is easy to do. Provisional tax is calculated on the basis of last year's earnings, plus 5 per cent, so if you do not do anything, the amount you have to pay keeps going up.