The queen bee levy is singled out as Australia's smallest tax in the discussion paper that will guide the 18-month review of Australia's tax system.

In 2006-07 the levy raised just $8000 from bee-keepers exporting queen bees, levied at the rate of 10c for each bee sold for more than $20 and 0.5pc of the price of bees sold more cheaply.

But, like many of Australia's smaller taxes, it costs a lot to collect.

The discussion paper says that out of every $100 collected, $21 is eaten up by the cost of collection.

The Nashi Pear Levy and Export Charge is the most expensive tax to collect, the costs eating up $30 of every $100 collected.

Many of these taxes, among them the Buffalo Slaughter Levy and the Lychee Levy have been introduced at the request of the producers being taxed.

The discussion paper makes the point that producers would rather trust the government to collect their money and hand it to their industry than they would trust each other.

Most of the $2602.5 billion raised in tax in 2006-07 came from just 10 taxes, the biggest being personal tax, company tax, the goods and services tax, and fuel excise.

For many of us, paying tax is neither complicated nor particularly painful.

Our tax take is the eighth lowest in the Organisation for Economic Co-operation and Development.

And contrary to widespread belief, the system isn't becoming more complex.

The discussion paper says that on almost every measure - pages of the income tax law, the use of tax agents, the time spent preparing business activity statements - the tax system is getting much simpler.

Launching the 343-page discussion paper in Melbourne, Treasurer Wayne Swan said its observations would challenge many people.

"I don't necessarily find that everything in this paper jells with everything that I have said on tax in the past, and that is as it should be.

"This is a Treasury discussion paper which is out there to promote discussion."